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Regional Oral History Office University of California

The Bancroft Library Berkeley, California

Arthur L. Schawlow

OPTICS AND LASER SPECTROSCOPY, BELL TELEPHONE LABORATORIES,
1951-1961, AND STANFORD UNIVERSITY SINCE 1961

With an Introduction by
Boris P. Stoicheff

Interviews Conducted by

Suzanne B. Riess

in 1996

Since 1954 the Regional Oral History Office has been interviewing leading
participants in or well-placed witnesses to major events in the development of
Northern California, the West, and the Nation. Oral history is a method of
collecting historical information through tape-recorded interviews between a
narrator with firsthand knowledge of historically significant events and a well-
informed interviewer, with the goal of preserving substantive additions to the
historical record. The tape recording is transcribed, lightly edited for
continuity and clarity, and reviewed by the interviewee. The corrected
manuscript is indexed, bound with photographs and illustrative materials, and
placed in The Bancroft Library at the University of California, Berkeley, and in
other research collections for scholarly use. Because it is primary material,
oral history is not intended to present the final, verified, or complete
narrative of events. It is a spoken account, offered by the interviewee in
response to questioning, and as such it is reflective, partisan, deeply involved,
and irreplaceable.

************************************

All uses of this manuscript are covered by a legal agreement
between The Regents of the University of California and Arthur L.
Schawlow dated May 3, 1997. The manuscript is thereby made
available for research purposes. All literary rights in the
manuscript, including the right to publish, are reserved to The
Bancroft Library of the University of California, Berkeley. No part
of the manuscript may be quoted for publication without the written
permission of the Director of The Bancroft Library of the University
of California, Berkeley.

Requests for permission to quote for publication should be
addressed to the Regional Oral History Office, 486 Library,
University of California, Berkeley 94720, and should include
identification of the specific passages to be quoted, anticipated
use of the passages, and identification of the user. The legal
agreement with Arthur L. Schawlow requires that he be notified of
the request and allowed thirty days in which to respond.

It is recommended that this oral history be cited as follows:

Arthur L. Schawlow, "Optics and Laser
Spectroscopy, Bell Telephone Laboratories,
1951-1961, and Stanford University Since
1961," an oral history conducted in 1996
by Suzanne B. Riess, Regional Oral History
Office, The Bancroft Library, University
of California, Berkeley, 1998.

Copy no.

This photograph shows a flash of light from a ruby laser breaking a blue inner
balloon without damaging the outer balloon. The red light from the laser
passes through the clear outer balloon, but is absorbed by the dark blue inner
balloon and produces a hot spot which breaks it. To show the balloon in the
middle of the brief instant of breaking, a photographic flash lamp is
triggered when the sound of the breaking balloon reaches a microphone. This
gives a one millisecond delay after the laser pulse.

Photograph by Kenneth Sherwin and Frans Alkemade

San Francisco Chronicle, April 30, 1999

Arthur Schawlow

Arthur Schawlow, a Stanford Uni
versity physicist and 1981 Nobel
Prize winner for his pioneering work
in lasers, died Wednesday at Stan
ford Hospital after a prolonged ill
ness. He was 77.

Professor Schawlow and Charles

Townes, professor emeritus of phys
ics at the University of California at
Berkeley and Professor Schawlow's
brother-in-law, shared credit for in
venting the laser, which made possi
ble fiber-optic telecommunications,
outpatient corrective eye surgery
and CD music players, among many
applications.

The two men developed the de-
sign for the laser in the 1950s and
built a working laboratory model in
1960. But they never made any prof
its from the discovery because they
were working for Bell Laboratories
at the time. Both men are in the
Inventors Hall of Fame in Akron,
Ohio.

A native of Mount Vernon, N.Y.,
Professor Schawlow was interested
in electrical, mechanical and astro
nomical things from childhood. He
earned bachelor's and graduate de
grees in physics from the University
of Toronto.

He met his collaborator, Townes,
a recognized leader in the field of
microwave spectroscopy at Colum
bia University, while on a postdoc
toral fellowship there.

In 1961, Professor Schawlow
joined the physics department at
Stanford, where he continued his
research in optical and microwave
spectroscopy, superconductivity
and lasers. He was popular among

students for both his science knowl
edge and his sense of humor.

At Stanford^ Professor Schawlow
was given the nickname "the laser
man" because of his popular class
room demonstrations of the way the
new tool he had helped develop
worked.

In a favorite illustration of the
laser's pinpoint selectivity, he used
what he jokingly called a "ray gun"
laser to shoot through a transparent
balloon to pop a dark Mickey
Mouse balloon inside without
damaging the outer one.

Stanford physicist and Nobel lau
reate Steven Chu recalled visiting a
physics lab where "The Sayings of
Art Schawlow" had been posted on
a wall. One example: "To do suc
cessful research, you don't need to
know everything, you just, need to
know one thing that isn't known."

Professor Schawlow is survived by
his son, Artie, of Paradise, Calif.;
daughters Helen Johnson of Stevens
Point, Wise., and Edie Dwan of
Charlotte, N.C.; and five grand
children.

A memorial service is planned at
Stanford University, but no date has
been scheduled.

Cataloguing information

SCHAWLOW, Arthur L. (b. 1921) Physicist

Optics and Laser Spectroscopy, Bell Telephone Laboratories, 1951-1961, and
Stanford University since 1961, 1998, x, 383 pp.

Schawlow family background, Depression years in Toronto; early aptitudes in
radio engineering; college and university studies in math and physics, and
WWII interruption; Malcolm Crawford and thesis research on atomic beam light
source; post-doc at Columbia University, 1949-1951; co-author, with Charles H.
Townes, of Microwave Spectroscopy (1955), dealing with theory and experimental
techniques of microwave Spectroscopy; marriage in 1951 to Aurelia Townes, and
move to Bell Telephone Laboratories: working on superconductivity, in 1957-
1958 collaborating with Townes on the optical maser (laser), and publication
of "Infrared and Optical Masers"; discussion of the atmosphere at Columbia and
at Bell Labs, pressures, publications, patents; joins physics faculty at
Stanford University: research group in laser Spectroscopy, Ted Hansch,
students, administrative matters, other faculty; interest in teaching,
motivation, ethical issues, funding and the military, telling stories, timing,
hindsight; expert jazz collector; Nobel Prize in Physics, 1981, and other
honors; son Arthur, Jr., and discussion of the treatment of autism.

Introduction by Boris P. Stoicheff, Department of Physics, University of
Toronto.

Interviewed 1996 by Suzanne B. Riess.

TABLE OF CONTENTS --Arthur Schawlow

INTRODUCTION by Boris P. Stoicheff i

INTERVIEW HISTORY vi

BIOGRAPHICAL INFORMATION ix

I BACKGROUND AND EDUCATION, TORONTO

Schawlow Family, Toronto Childhood 1

Religious and Cultural Milieu 7

Early Interest in Engineering and Science 10

High School, Vaughan Road Collegiate Institute 16

Some Beliefs, and Some Disbeliefs 19

Entering College, University of Toronto 23

Physics in the Prewar and War Years 27

Radio, Scouting, and Jazz Music 31

Seeing the Possibilities in a Career in Physics 38

Thoughts on Emigre Physicists, and Family Support 42

Graduate School YearsThe Master's Degree 45

Research Enterprises Ltd., Wartime Research, the Bomb 50

Graduate School YearsAtomic Beam Light Source 56

Crawford and Welsh, and Women Students 66

Hindsights 68

II COLUMBIA UNIVERSITY

Carbon and Carbide Fellowship 72

Charles Townes and the Microwave Spectroscopy Book 76

Meeting and Marrying Aurelia Townes 80

Theoretical Work, and Publishing on Hyperfine Structure 83

The Atmosphere at Columbia, 1949 85

Publications and Timing 87

Seminars and Group Meetings 89

Looking for OH 91

The Subject of Equipment 94

Nepotism Necessitates a Job Search 96

More on Writing the Microwave Book with Townes 98

III BELL LABS YEARS

Experiments on Superconducting Phenomena 102

Research, Resources 107

Murray Hill, and the Work Day 110

Madison, and Home Life 113

Stan Morgan and the Solid State Group 115

Working up to the Laser 120

Mode Selection 124

About the PatentThe Smell of Success 127

Looking at MaterialsRuby 130

Ted Maiman's Work, and Publication 135

Pressure Results in Exhaustion, 1960 141

Publishing with Bell Labs The Clad Rod Laser 144

Time to Leave Bell Labs 146

National Inventors Hall of Fame, 1996 150

Laser Action in Ruby- -Physical Review Letters Feb. 1, 1961 152

Inventing Stuff 156

Science Writers, Informing the Public 158

Post-Laser Atmosphere at Bell Labs 160

Gordon Gould and the Competitive Drive 161

IV THE EARLY YEARS AT STANFORD, AND FAMILY 167
The Department, Plain and Applied 168
Felix Bloch, Robert Hofstadter, Bill Fairbank 170
And SLAG 172
The Big Picture: Teaching, Labs, Students, Postdocs 176
And Administration: Department Chair, 1966-1970 180
The Family 187

Settling into Palo Alto 187

Autism and Artie 188

Helen and Edith 200

V WORK AND STUDENTS

Secrecy, Motivation, and Morality 209

Uses of the Laser, Unusual and Medical 213

Funding and the Military 217

Facilities at Stanford 222

"Science in Action" and Other Honors 226

Some Russian Physicists 229

People and Projects 233

Optical Science 233

Mollenauer, Imbusch, Emmett, McCall 234

Titanium in Ruby Rods 239

Light-controlled Chemical Reactions 241

Consultancy at Varian 243

The Hodgepodge of Projects, Ray Gun, Full House in the Lab 244

Fortunate Conjunction 248

Travelling 248

Ted Hansch, and Edible and Tunable Lasers 250

Doppler-free Spectroscopy 252

Brillouin Scattering: Marc Levenson 254

R.R. Donnelley Co. Project in Switzerland 255

Cooling with Laser Light, and Other Good Ideas 256

Tower of Babel 258

More on Laser Cooling 260

VI ACCOMPLISHMENTS AND QUESTIONS

General Look at How Schawlow Works 263

Prize-Winning Work: Rydberg Constant 267

Quantum Electrodynamics 269

Hyperfine Structure of Iodine 273

The Apostolic Succession Phenomenon 275

National Ignition Facility Work, and the Military Sponsorship 276

Work and Publications with Students 277

Chinese Physics Graduates 282

Summing up the Seventies 285

News of the Nobel PrizePutting the Money to Work for Artie 287

Current Work 291

Thinking in Classical Pictures 293

A Few Last Stories to Tell 294

TAPE GUIDE 300

APPENDIX

A Publications 302

B Four pages excerpted from Toronto Jazz, A Survey of Live

Appearances and Radio Broadcasts of Dixieland Jazz Experienced in
Toronto During the Period 1948-1950, by Jack Litchfield. 316a

C "From Maser to Laser", by Arthur L. Schawlow, in Impact of Basic
Research on Technology, Kursunoglu and Perlmutter, editors, Plenum
Press, New York-London, 1973. 317

D "Masers and Lasers", by Arthur L. Schawlow, Fellow, Institute of
Electrical and Electronics Engineers, from IEEE Transactions on
Electron Devices, Vol. ED-23, No. 7, July 1976. 354

E "Never Too Late, Communication With Autistic Adults", by Aurelia
T. Schawlow and Arthur L. Schawlow, in Proceedings of the NSAC
(now Autism Society of America) National Conference, July 1985. 361

F "Our Son: The Endless Search for Help," by Aurelia T. Schawlow and
Arthur L. Schawlow, in Integrating Moderately and Severely
Handicapped Learners, Strategies that Work, Brady and Gunter,
editors, Thomas Books, Springfield, Illinois, 1985. 370

INDEX 383

INTRODUCTION by Boris P. Stoicheff

ARTHUR LEONARD SCHAWLOW

The many contributions to science of Arthur Leonard Schawlow as a
teacher, science writer, and creative physicist have won for him a
renowned national and international reputation, highlighted by the award
of the Nobel Prize in Physics in 1981, and the National Medal of Science
in 1991. Two prestigious Arthur L. Schawlow Awards, given annually,
honour him as one of the laser pioneers: a Medal of the Laser Institute
of America for laser applications, and a Prize of the American Physical
Society for contributions to laser science. On a more personal note has
been the adulation of his many students and co-workers who published a
volume, Laser Spectroscopy and New Ideas: A Tribute to Arthur L.
Schawlow, on his 65th birthday in 1986, and who also organized The
Arthur Schawlow Symposium on his retirement five years later. These
were heart- felt gatherings of the many people whom he had touched with
his friendship, consideration, and joy and wonder of science.

Arthur was born in Mt. Vernon, New York, but his family moved to
Toronto, Canada in time for him to take his primary and secondary
education there. His sister Rosemary recalls that Art had some problems
in early school. In fifth grade, one of the teachers made life
miserable for Art in public school, so that the family was advised to
register him at another school, the Normal Model School where teachers
were being trained. His progress was very good in everything but
writing and art. Under a teacher's pressure, his writing improved, but
his clumsy hands, by his report, were no good for drawing. When he
proceeded to high school, at Vaughan Road Collegiate, to avoid art he
enrolled in bookkeeping and typewriting rather than in art and botany.
Nevertheless, he was in the academic stream and took the other usual
subjects for university entrance. Art graduated with an excellent
record, and enrolled in one of the most demanding programs of
Mathematics and Physics at the University of Toronto. Thus began his
career in science. He continued in graduate studies, obtaining a Master
of Arts degree, followed by his Ph.D. degree in atomic physics in 19A9,
under the supervision of Professor Malcolm F. Crawford.

It was in 1948, when I began graduate research at Toronto, that I
first met Art. His experiment in atomic beam spectroscopy and hyperfine
structure was located in the basement of the McLennan Physical
Laboratory, where he spent most of the day with his co-workers Fred
Kelly and Mac Gray, while I was with the molecular group on the fourth
floor. This was an extremely active period, with many returned
veterans, all working furiously to all hours of the night. We would
meet at tea time and at colloquia. And once experiments were in

progress, we seemed to have time to visit each other's labs because
photographic exposure times were tens of hours, since this was the
traditional method for detecting and recording spectra in those early
years. It was a special pleasure to visit the basement lab, where often
in the evenings Art would be serenading his atomic beam with the
clarinet, which he played reasonably well. His idols were Benny Goodman
and "Jelly Roll" Morton, and his repertoire mainly Dixieland jazz.

By that time, Art had an enviable collection of jazz records. He
and his sister Rosemary started collecting while in high school, by
buying used juke box records. This expanded to a full fledged hobby
later when he was better able to afford this pastime, and also to record
the music himself as tape recorders became available. As his science
progressed, he was able to travel to conferences in various cities, and
to devote some evenings to music halls and jazz.

Art and his colleagues published seven papers on their doctorate
research including details of their apparatus and spectroscopic results.
While each member of the team was responsible for designing and building
an important part of the equipment and seeing to its proper working in
the experiment, they each became acquainted with every piece of
apparatus in the experiment. This turned out to be important to Art's
later basic contribution to the laser; the two end mirrors which form
the resonator are an adaptation of a device (the Fabry-Perot
interferometer) used in the atomic beam experiments in the McLennan
Laboratory. Art achieved early recognition for his research in atomic
spectroscopy and received a postdoctoral fellowship to work at Columbia
University. There began his long and fruitful association with Charles
H. Townes, a pioneer of microwave spectroscopy, whom he first met at an
American Physical Society meeting in April 1949.

At Columbia University, Art began research on the diatomic
molecule OH using the new technique of microwave spectroscopy, and
having difficulty in finding its spectrum he coined the memorable line,
"a diatomic molecule is a molecule with one atom too many." He also
began writing with Townes the book titled Microwave Spectroscopy, one of
the first volumes in this field. Just about that time, Townes was
involved with development of the MASER, and he tells the following story
of how the idea of the MASER occurred to him. In April of 1950, he and
Art were attending an American Physical Society Meeting in Washington,
D.C., and they shared a room in the Franklin Hotel. Art, being a
bachelor, was used to sleeping late, and Charlie, being married with
four young daughters, would be up very early. So, waking up early as
usual, and not wanting to disturb Art, Charlie dressed and went out to
nearby Franklin Park. It was there, sitting on a bench, thinking about
a government committee meeting he would be attending that afternoon on
trying to find better ways of producing radiation shorter than
millimeter wavelengths, that the idea of the MASER hit him. As Art

ill

likes to point out, his own inadvertent contribution was crucial:
"Imagine the result if I had wakened early!"

In May 1951, Art married Aurelia Townes, Charlie's younger sister,
a fine musician and vocalist, and they raised a family of a son and two
daughters. In the fall of that year, Art was employed by Bell Telephone
Laboratories in Murray Hill, New Jersey and carried out research in
superconductivity. His contacts with Townes continued, as Art spent
many a Saturday at Columbia completing the book, Microwave Spectroscopy,
published in 1955, and Townes was consulting for Bell Labs. Their
collaboration on the possibility of extending the range of the maser
into the visible region culminated in their famous paper of December
1958, "Infrared and Optical Masers," which established the principles of
the LASER. Within two years, the first working device, the pulsed ruby
laser, was developed by Theodore Maiman at Hughes Research Laboratories,
soon followed by the helium-neon laser introduced by Ali Javan and
colleagues at Bell Labs, and the era of the LASER was launched. The
laser spawned a flourishing new field of science and technology, now
known as "Quantum Optics", and a huge industry, commonly called
"Photonics and Electro-Optics." And over the years, Art has been a
continual contributor to the imaginative use of the laser in science,
communications, engineering, and medicine.

With his appointment as Professor of Physics at Stanford
University in 1961, Art became a major influence in the lives of many
young scientists. In no time, he gathered around him a large group of
able students, and a constant stream of visitors from many countries
soon followed. His students enjoyed the fatherly advice given with
Art's usual sense of humour and understanding: "To do successful
research, you don't need to know everything, you just need to know of
one thing that isn't known"; and, "Anything worth doing is worth doing
twice, the first time quick and dirty, and the second time the best way
you can." And when science fiction writers and journalists wrote about
the death ray, and produced posters of "The Incredible Laser", showing
laser cannons firing at rockets, Art's answer was that all one had to do
was to polish the outer surfaces to reflect back the beam of light. In
his own laboratory, he mounted such a poster on the door, adding the
subtitle, "For credible laser see inside." In this heady atmosphere
with its special "magic", the Schawlow Laboratory was one of the
outstanding contributors in laser spectroscopy, producing many new ideas
and techniques which became standards in the field.

During this early period of the laser, Art was deluged with
invitations to write articles for the lay public, and to lecture to a
variety of audiences all over the world. He accepted an exhausting
schedule of travel, and charmed and informed audiences with his
characteristic flair for telling anecdotes and performing
demonstrations. One of his favourite and most vivid lecture
demonstrations was to use his portable "ray-gun laser" to burst a blue

Mickey Mouse balloon placed inside a clear outer balloon, without
damaging the outer balloon. This same idea had important consequences
since it was applied to remedy retinal detachment with the laser: the
lens of the eye transmits the red laser light, but the retina absorbs it
and is heated sufficiently to weld the retina together. Art found the
requisite balloons in the San Francisco Zoo, which he visited each month
to stock up on his supply. One Sunday, when parents with disappointed
children questioned the Sold Out sign for double balloons, they were
told by the proprietor, "A crazy professor just bought out the entire
stock!" Some demonstrations were carried out without apparatus, as when
Art reminded audiences of the Doppler Effect, and moving towards the
audience he elevated the pitch of his voice, and moving away he lowered
the pitch.

Art's ad libs at seminars and colloquia are legendary. On one
occasion he was speaking at Stanford on the topic, "Is Spectroscopy
Dead?" He immediately defined what he meant by spectroscopy, and
proceeded to give his talk, when Professor Felix Bloch asked, "What do
you mean by dead?" Art blurted out, "Oh, when the chemists take over,"
to which he added his infectious laugh, and everyone else joined in,
although chemists in the audience were not amused. Of course, Art went
on to say that that was what happened to microwave spectroscopy, now
done mainly by chemists and few physicists, so that chemists know much
more about molecules. I vividly remember when he introduced me at a
Stanford colloquium, and having given a brief biography, stressed that
my undergraduate and graduate degrees were from the University of
Toronto, and then emphasized, "...so he is very well-educated," followed
by his belly-shaking laugh, knowing full well that his Stanford
colleagues were aware that he too studied at Toronto. In Art's case, we
added an Honorary Doctorate Degree in 1970 to make a total of four
degrees from the University of Toronto, and branded him an "Exceedingly
well-educated man."

Among Art's later contributions to science, two carried out with
Ted Ha'nsch, then his colleague at Stanford, stand out. One was
seemingly frivolous, and related to Art's contention that "anything will
lase if hit hard enough." They experimented with various flavors of
Knox Jello in an effort to make an "edible laser." Finally, they added
sodium fluorescein to clear gelatin and, lo and behold, when pumped by
an ultraviolet laser, green laser light was produced. Later, colleagues
at Bell Labs used gelatin film to demonstrate the first "distributed
feedback laser", a form of laser which today plays an important role in
optical communications. The second contribution was the seminal idea of
cooling gas atoms by laser radiation pressure. This method was
developed at several laboratories and used to cool gas atoms to almost
absolute zero, leading to the award of the 1997 Nobel Prize in Physics
to three of their friends, Steven Chu at Stanford, Bill Phillips at
NIST, and Claude Cohen-Tannoud j i in Paris.

Along with these many scientific successes and accolades, Art and
Aurelia lived graciously with a heart-rending sadness, the care of their
nonverbal autistic son, at home and later at medical institutions.
While in Sweden, at the time of the Nobel Award, Art learned of a hand
held communicator, and with that device and special calculators they
were able to improve communication with their son. Art and Aurelia
later helped to organize a nonprofit corporation, California Vocations,
a group home for autistic people. A further tragedy was the death of
Aurelia in 1991, while on her way to visit their son, living about two
hundred miles from Palo Alto.

It has been my good fortune to also work in laser spectroscopy,
and to keep in close contact with Art Schawlow over the years. He has
been a valued friend and inspiration, and one constantly remembered for
helping to bring to the world "A Wondrous New Light."

Boris P. Stoicheff

University Professor of Physics, Emeritus

April 1998
Toronto, Ontario,
Canada

vi
INTERVIEW HISTORY- -Arthur Schawlow

Arthur Schawlow, winner of the Nobel Prize for Physics in 1981 for
his contributions to the development of laser spectroscopy, and a
Californian since 1961, is a stellar member of the group of fine
scientists, in particular physicists, who came west in the sixties, often
redirecting their research focus at mid-life. Leaving behind a career that
had been centered at Bell Telephone Laboratories, Professor Schawlow chose
to bring his work and his family to Stanford University. There he taught
and took on administrative responsibilities, and with his students and his
colleagues completed major research that has advanced the knowledge and
applications of laser science and spectroscopy.

This brief interview history will not summarize Arthur Schawlow 1 s
achievements. Boris P. Stoicheff has done that very well in the
introduction he has graciously contributed to the memoir. A two-page
biography, extensive bibliography, and other documents appended demonstrate
the range and extent of the scientific pursuits and publications of
Professor Schawlow. It is assumed that an historian of science will refer
to Professor Schawlow 1 s writings for a more precise chronology of the
development of laser spectroscopy.

In undertaking to conduct an oral history with Arthur Schawlow it was
my particular ambition to articulate the excitement and energy of moments
of discovery, the life of the laboratory, and the total commitment to the
work that informs the science of Arthur Schawlow. All that, as well as to
get onto paper his humor and rare personal qualities. And I was not alone
in such an ambition.

The reason Professor Schawlow agreed to the request of the Regional
Oral History Office to do an oral history, to take the time, and to summon
up the emotional fortitude often required for the interviews, as well as
the time for checking and editing, was because for him the manner in which
one puts the point across is keenly important to the story, whether in
talking to the interested general public or his students or his peers. He
wanted to illustrate the pleasures of his profession. He had begun to
write an autobiography, and he felt that doing an oral history would
facilitate that writing.

My first encounter with Professor Schawlow was through interviewing
Charles H. Townes. Arthur Schawlow wrote the introduction to the 1995
Townes oral history, A Life in Physics: Bell Telephone Laboratories and
World War II; Columbia University and the Laser; MIT and Government
Service; California and Research in Astrophysics. The two men are
colleaguesoriginally Schawlow was a graduate student at Columbia working
with Townes--and they are co-authors, and related through marriage. That
rare combination of relationships is very strong.

vii

Here is what Schawlow wrote in his introduction to Townes: "It was
Frances Townes [the wife of Charles Townes] who made sure that I became
acquainted with Charles' younger sister, Aurelia... Although everything I
have done in physics since then has been enormously aided and influenced by
what I learned from Charles Townes, I have to say that meeting Aurelia was
the best thing that happened to me in New York." That quote, with its
underlying humor, is not hyperbole.

However, as the reader will learn, the life that Arthur and Aurelia
Schawlow shared required far more than the usual wedded commitment because
of the sad and very difficult practical family problem for them, and their
daughters, of the quality of the life of their severely autistic first
child, their son, Arthur, Jr. This issue is discussed fairly openly in the
oral history. It is still very emotionally charged, very present, and it
requires much of Professor Schawlow 1 s time. The death in an automobile
accident in 1991 of his wife Aurelia doubled his responsibility for his
son, and dimmed the light of his life.

The oral history interviews began with my first meeting Professor
Schawlow at his two-room apartment in Palo Alto. From there we set off in
his car to his office at Stanford. I was immediately struck by the sheer
amount of technology he surrounded himself with. Both locations were
replete with computers, terminals, hookups, cables and tables, and books.
It came as no surprise that he was adept with this technology, and that his
office was bristling with it, but the fact that he lived so much in its
midst at home was striking.

Equally striking, and completely delightful, was the mitigating
presence of an impressive jazz music tape and CD library lining his living
room walls. The sound of music leavened the table- top technology. After
our two-hour morning interview sessions were finished sometimes I would be
treated by Professor Schawlow to a particularly choice musical interlude,
always jazz, perhaps taped from a live performance using clever, sensitive,
and pocket-sized equipment! I was the recipient of the gift of two of the
best tapes, technically, that anyone has ever made for me, and I listened
to Bob Crosby's band as I drove between Berkeley and Stanford for our eight
interviews, from August to November, 1998.

Doing an oral history, delving into the past, reviewing struggles and
successes and looking at causes and outcomes, usually amounts at the very
least to a diverting experience for the interviewee. However, I would say
that our interviews, productive and pleasant as they very definitely were,
could not distract from a feeling of a the missing center and balance in
Professor Schawlow' s life in 1996. He had only just moved from the
Schawlow' s family home in Palo Alto to a retirement community. Limited
space, social readjustments, and relearning the bachelor life after long
married yearsdealing with such household practicalities as acquiring a
sink big enough to wash a pot inthis stuff challenged Arthur Schawlow' s
natural good humor.

viii

Having said all that, it was also manifest that Professor Schawlow
was not disappearing into retirement. During our interviews he was and
certainly continues to be much in demand. Attending meetings and what
appears to be an endless cycle of award presentations kept him flying more
than he would have wished. Yet when it came time to edit the transcripts
that I had reviewed and organized with chapter headings, Professor Schawlow
was very responsive to my queries, meticulousnot changing the text, but
clarifying the meaning. If there are any errors in the oral history it is
our fault, not his.

Laser, spectroscopythese words are associated with intense, bright
searching light, healing light, measurement, the furthering of knowledge.
The reader will meet a man who has contributed his life to the search, and
get a good sense of how he thinks, how he picks his problems, how he goes
about solving them, and how he delights in the challenge.

The Regional Oral History Office, a division of The Bancroft Library,
was established in 1954 to record the lives of persons who have contributed
significantly to the history of California and the West. Other oral
histories in science and technology are available through the Office, which
is under the direction of Willa K. Baum.

Suzanne B. Riess
Interviewer /Editor

May 1998
Berkeley

ARTHUR L. SCHAWLOW
(Biography)

Arthur L. Schawlow was born in Mount Vernon, New York. He received the
Ph.D. degree from the University of Toronto in 1949. After two years as a
Postdoctoral Fellow and Research Associate at Columbia University he became a
Research Physicist at Bell Telephone Laboratories. In 1960, he was a
Visiting Associate Professor at Columbia University. Since 1961, he has been
a Professor of Physics at Stanford University. He was Chairman of the
Department of Physics from 1966 to 1970; Acting Chairman, 1973-74, and in
1978 was appointed J.G.Jackson and C.J.Wood Professor of Physics.

His research has been in the field of optical and microwave
spectroscopy, nuclear quadrupole resonance, superconductivity, lasers, and
laser spectroscopy. With C. H. Townes, he is coauthor of the book,
Microvave Spectroscopy, and of the first paper describing optical masers,
which are now called lasers. For this latter work, Schawlow and Townes were
awarded the Stuart Ballantine Medal by the Franklin Institute (1962), and the
Thomas Young Medal and Prize by the Physical Society and Institute of Physics
(1963). Schawlow was also awarded the Morris N. Liebmann Memorial Prize by
the Institute of Electrical and Electronics Engineers (1964).

Dr. Schawlow received a Nobel Prize for Physics in 1981 for "his
contribution to the development of laser spectroscopy."

Schawlow was named California Scientist of the Year in 1973. In 1976,
he was awarded the Frederick Ives Medal of the Optical Society of America "in
recognition of his pioneering role in the invention of the laser, his
continuing originality in the refinement of coherent optical sources, his
productive vision in the application of optics to science and technology, his
distinguished service to optics education and to the optics community, and
his innovative contributions to the public understanding of optical science."
In 1977, he was awarded the Third Marconi International Fellowship. Schawlow
also received a Golden Plate Award from the American Academy of Achievement
in~1983. In 1991, he received a U.S. National Medal of Science for "his role
in the conception of the laser and advancing its applications, particularly
to laser spectroscopy."

In 1982, the Laser Institute of America established the

Arthur L. Schawlow Medal for laser applications, to be awarded annually. The
first medal was awarded to Schawlow "for distinguished contribution to laser
applications in science and education." The American Physical Society
established the Arthur L. Schawlow Prize for laser science in 1990. In 1996
he became a member of the American Inventors Hall of Fame, and also received
the Ronald H. Brown American Innovator Award from the U.S. Department of
Commerce. He also received the Arata Award of the Japan High Temperature
Society.

He has received honorary doctorates from the University of Ghent, Faculty
of Science, Belgium, 1968; University of Toronto, Canada, 1970 (Ll.D.);
Bradford University, England, 1970 (D.Sc.); University of Alabama, USA, 1984
(D.Sc.); Trinity College, 1986, Ireland (D.Sc.); University of Lund, Sweden,
1988 (D.Tech.): Victoria University, Toronto, Canada D.S.L. (1994). He is an
Honorary Professor of East China Normal University (1979) .

Schawlow is a Fellow of the American Physical Society (Member of
Council, 1966-1969), the Optical Society of America (Director-At-Large,
1966-1968), the Institute of Electrical and Electronics Engineers, the
American Association for the Advancement of Science, the American Academy of
Arts and Sciences, the American Philosophical Society, the Institute of
Physics (Great Britain), and a Member of the U.S. National Academy of
Science. He was Chairman of the Division of Electron and Atomic Physics of
the American Physical Society (1974), President of the Optical Society of
America (1975), and Chairman of the Physics Section of A.A.A.S. (1979). He
was President of the American Physical Society in 1981. He was Chairman of
Commission C.15, Atomic and Molecular Physics (1978-1981), and Chairman of
the U.S. National Committee for the International Union of Pure and Applied
Physics (1979-1982) . In 1983 he was elected one of six Honorary Members of
the Optical Society of America. He is an Honorary Member of the Gynecologic
Laser Society and of the American Association for Laser Medicine and Surgery.
He is also an honorary member of the Royal Irish Academy (1991).

Dr. Schawlow wrote the introduction for Scientific American Readings on
Lasers and Light, and three of the articles in that collection; he is author
or coauthor of over 200 scientific publications. On television, he has
appeared on one of the 21st Century programs with Walter Cronkite, and one of
the Experiment Series with Don Herbert, as well as on films for Canadian,
British, Japanese, and German T-V networks.

April, 1998

I BACKGROUND AND EDUCATION, TORONTO

[Interview 1: August 14, 1996] II 1

Schawlow Family, Toronto Childhood

Riess: Please start in at the beginning and tell me what you can about
your parents. You said last time that you didn't know that
much family history, but you'll want to include what you can
recall.

Schawlow: Yes. I was born in Mount Vernon, New Yorkand my birth

certificate says so--on May 5, 1921. We didn't live there very
long: my parents moved, I understand, to New Rochelle, and then
when I was about three years old, they came to Toronto, Canada.

My mother was born in Canada, grew up there, and she never
wanted to talk much aboutneither of my parents wanted to talk
much about their early life. I think it was a fairly large
family, because occasionally we'd meet a brother or sister
who'd come to town and visit. But she claimed that her father
was a mounted policeman at one time. I talked with a cousin
who claimed that they were all farmers. I don't know. She
said she was born in Petacodiac, British Columbia, which is a
small town, which might have been a place where a mounted
policeman would be living, but she grew up in Pembroke,
Ontario.

I think that her mother died when she was born, and her
father died about six years later. I think he remarried, but
then after he died the family was broken up, and she lived with
various people at various times, sometimes with her sister
Mary, and that was not happy at all. Mary was an older sister,
considerably older. She spent some time in a convent school.
I think their family was Catholic, but she wasn't by the time I

'II This symbol indicates that a tape or segment of a tape has begun
or ended. A guide to the tapes follows the transcript.

met her [laughter] --knew her, rather,
about her.

So I don't know much

Cecilia lived in Pembroke; we knew her then, and she was my
mother's favorite sister. Cecilia made wonderful doughnuts, I
remember. And she had a son, Heber, who was about my age. We
visited them in Pembroke a few times, and had a very pleasant
time.

During the war, Cecilia's husband, Percy Jessup--her
married name was Jessup--was a plasterer. But he moved to
Toronto and I think he had a job as a guard or something at a
war plant, and then he died. They lived in the outskirts of
Toronto for some time. My mother had another brother, Dan
both of these were considerably olderand Dan worked in a
transformer factory, General Electric Transformer. He was a
millwright; I didn't know what that meant, but I think now it
means a man who moves things around the mill, does the heavy
moving. He was a bachelor for a long, long time and he used to
come to Sunday dinner very often, and he'd usually bring a
brick of ice cream. That's the way ice cream came in those
days, usually from a drug storethat was the only place that
was open on Sunday the ice cream was in bricks.

Riess: How did your mother meet your father?

Schawlow: Well, it's a rather mysterious thing. On my birth certificate
her name is listed as Helen Mason, and her brother's last name
was Carney. But I think some of the other brothers, younger
brothers or half-brothers, are named Mason. So I don't know
how that happened. But at any rate, I think for a while she
worked as a practical nurse or assistant to nurse. Then she
went to New York, I think to work with somebody there as a sort
of nursing assistant. During the war, Metropolitan Life
Insurance Company was very short of help and I think she worked
with them, and that's how she met my father.

My father had come from Latvia. He was born in Riga, and I
don't think he was legally in the United States or, for that
matter, in Canada.

Riess: Was he an ethnic Latvian?

Schawlow: He was Jewish. We didn't know it at that time. He didn't tell
us until we were grown up. There was a lot of anti-semitism in
Toronto. I don't think there were any Jewish professors. So
my mother brought us up as Protestants in the United Church of
Canada, which was formed in 1925, I think, as a union of the
Methodists, Congregationalists, and half the Presbyterians the

more fundamentalist Presbyterians continued as the Presbyterian
Church. We were brought up as Christians, and I didn't know my
father was Jewish. I don't think he was really religious, but
his background was. And he didn't tell me until I was about
seventeen or something like that.

Riess: What was the occasion for telling you?
Schawlow: I don't remember exactly, but he did tell me.

Riess: When I ask about being an ethnic Latvian, the Latvian culture
is very strong, and full of traditions. I wondered if he had
any of that .

Schawlow: Well, it's hard to tell. He certainly didn't show it. I think
there were a number of people in the Baltic states who were of
Germanic origin, and particularly Jewish people, and they
probably behaved more as German Jews than as Latvians . But
this is conjecture. He told us various stories when we were
little, which I didn't believe, like he said he came from
Georgia and then he talked later about skating across the ice
to go to school. [laughs] Well, that didn't fit together, but
somehow I had more respect for my parents and I didn't question
that.

Riess: Was he humorous?

Schawlow: Yes, at times. He worked very hard.

Let's go back into his history, what I know. He certainly
had some mathematical ability, and he wanted to be an engineer.
So he went to Darmstadt in Germany to study, and he got there
too late for the start of the term, so he went on to visit one
of his brothers in the United States. He, too, had a large
familythis was the only one of his brothers I ever saw, his
brother John, whose name was Schwartz. I'm told that there was
some kind of a scandal and he changed his name . He ran a
tobacco store and news store in Lambertville, New Jersey. Some
of them changed their names: one's a Shaw, somebody's a Low,
and I think there's even a brother in South Africa. There was
one in Baltimore--! have my father's watch, a gold pocket watch
which says "Welcome to Baltimore," and I think it's dated 1910
or something like that.

Riess: Schawlow was the original. Your father kept the name.

Schawlow: Yes, I have his birth certificate, which is in Russian,

actually. Latvia was controlled by Russia in those days. It
was only free for a while between the wars, I think, and then
again recently.

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

So he came to visit his brother since he couldn't matriculate.

Yes, that's right. And then he got this job with the insurance
company, and that's how he met my mother.

As I say, I don't think he was really legally in the United
States. Coming to Canada, they told me at one point that you
couldn't come with a job, it wasn't allowed. So he resigned
from Metropolitan Life. Then after he got to Canada the
resignation was declined, so he was able to go back to work for
Metropolitan Life Insurance. He was very good, he was one of
their top people in the office. He at one point was an
assistant manager.

You said that he had mathematical abilities,
was using in his job?

This is what he

Well, I don't think he could use very much of it. It was a
horrible job. He had to go out every night to collect, because
the basis of the Metropolitan Life Insurance Company, which at
that time was the largestit was so-called industrial
insurance, which was weekly premiums for the working man. He'd
go out and kind of collect a quarter here, a nickel there.
Particularly during the Depression, it was very hard. But he
never lost his job and managed to scrape through. And we never
felt poor. We sort of knew what we could do, and we were
always well-fed and clothed.

It sounds like both parents, in a way, made a move that denied
their religious background, and a lot of their background. I
think that would be hard for them.

Yes, I suppose so. I think it must have been, although we
never really did get to discuss it.

And your sister is older than you?

Yes. I like to joke that I was named after my sister, about a
year and a half after. [laughter)

That's cute.

She's tired of hearing that. Her name is Rosemary Wolfe. Her
husband was a professor of geography at York University in
Toronto. He's been retired for some years, and they still live
in Toronto. She got a bachelor's degree in English literature
and got a master's degree, and then later went back and got a
library degree and worked for a while in libraries and for a
while in bookstores. But she hasn't worked for a long time.

Riess:
Schawlow:

What are your earliest memories?
Vernon at all?

Do they go back to Mount

Riess:

Schawlow:

No. I understand that when we came to Toronto we briefly had
an apartment or a flat or something on Pape Avenue, but I don't
really remember that at all.

What avenue?

P-A-P-E. Then we moved to 408 Sackville Street, but we weren't
there very long because most of the time we were there it was
at 436 Sackville Street. We lived there until I was eleven.
Just about when I was going into high school, my father moved
to a different office, which was then on the edge of town
actually in York Township, which was a separate municipality.
There is now a metropolitan government.

Reading the autobiography that you've written, I wondered
whether you ended up with a sense of moving around all the time
and uprootedness? 1

Well, a little of that, yes. This early stuff didn't make much
impression on me, I was too young. But moving to the suburbs
was hard. I had a very close friend next door, Gordon Kendall,
and it was a sort of wrenching experience. We would talk very
frequently on the phone for a while, and then gradually lost
contact.

Riess: You described a back yard in one of the houses that could
become an ice rink.

Schawlow: That was at A36 Sackville Street. It was hardly bigger than
this room, actually. It was very small. But the winters,
sometimesnot every year, some years it would be cold enough,
you'd just flood it and you'd have ice. You couldn't skate
very far because, as I say, it was small oh, maybe twenty feet
square.

Interestingly enough, the house is still there. I went
back a couple of years ago and took some pictures. The only
thing that's changed from the outside is that they have a
veranda or porch all the way around two sides it's on a
corner and instead of having a wooden railing, it now has a
metal railing. That's about the only thing I could see that
obviously was changed from the outside.

'Arthur Schawlow had begun an autobiography that he loaned to the
interviewer for background information.

We had the ground floor. There was an elderly couple
living upstairs, the Duffs. He, I gather, was a member of the
MacDuff family from Scotland, sort of an aristocratic family.
We heard a rumor that when he married his wife, that somehow or
other they disowned him. Anyway, I don't know about that. He
was a lawyer, worked for the city. They were pleasant people,
but we didn't have much to do with them.

Riess: Toronto, to the extent that I know about it, and it's mostly
from literature, is a kind of immigrant city.

Schawlow: Even more so now, yes. Well, at that time, yes. See, this was
not long after World War I, and there was a lot of immigration
from the British Isles, so a lot of English, Irish, Scotch--
"Scottish," as they prefer. In fact, somebody was telling me
yesterday that he asked somebody if he was Scotch, and he said,
"Either Scottish or a Scot. Scotch is something you drink."

We did have some good friends, like the Anguses, that were
real Scots, and I've always felt a liking for Scots since then.
Both their children were deaf, Elma and her brother were pretty
deaf, but Elma became quite expert at Highland dancing. We
were invited once to watch her rehearse in a living room, oh, I
don't know, maybe fifteen feet square, and there was a
bagpiper. I've never heard any noise as loud as that! A
bagpiper in a little room like that!

[laughs] Was that before or after you had your tonsils out?
Maybe it affected your hearing?

That was probably after, I think. [laughs] I don't think that
one evening, an hour or so of bagpipe, would have affected my
hearing.

Another incident you talk about in the autobiography was when
you were rescued by a babysitter. Was this seriously a near
drowning?

Yes, she thinks so. [chuckles] I wasn't worried. I felt I
was all right, but apparently I was getting in over my depth.
It was in the lake, Lake Ontario, which is an enormous lake.
It was a beach at a town called Scarborough. I don't know, I
wasn't worried, but she came out and grabbed me, and maybe I
would 've drowned otherwise. But I didn't feel that I was
drowning. Helen is still around, I saw her a year or so ago.

Riess: Helen was the babysitter.

Schawlow: Yes, Helen Egan--and her brother, Vincent, and I used to play
together.

Riess:

Schawlow:

Riess :

Schawlow:

Religious and Cultural Milieu

Riess: Where has this background left you with religion?

Schawlow: Well, I'm a fairly orthodox Protestant. I've been in a lot of
Protestant churches. I have to laugh--! don't know whether I
put it in there [autobiography]: one time, Vincent Egan said,
"You're a Protestant." And I said, "I'm not, I'm an American.'
I'd never heard the term Protestant before. But as we moved
around we were always in the United Church- -when we were in
Toronto. And when I went to New York I went to the Riverside
Church, which is affiliated with the Baptists but really is
nondenominational .

Then, after I got married, my wife got a job as organist
and choir director of the Baptist Church in Morristown [New
Jersey] . This Baptist church is not at all what you think of
as Baptist; it's a very liberal, Northern Baptist church. The
minister was very much interested in interracial friendships
and inter faith and so on. So we went there. Then, when we
came out to California, after a while Aurelia got a job at the
Congregational Community Church in Ladera, which is on the
outskirts of Palo Alto.

Riess:

Schawlow:

After we had the third child the job was too much, so we
started going to a Methodist church in Madison, New Jersey,
while we were still in New Jersey. That was ok. But then we
moved to California. We've been in Presbyterian and
Congregational churches around Palo Alto. Recently my son and
I both joined the Methodist Church in Paradise, California, and
that's the only one I go to now.

So, I don't know--I don't like to be pushed on what exactly
I think about religion, because I think a lot of it I don't
know. But I think the world is too wonderful to have just
happened. And I think that orthodox Christianity is a good
conduct for life, and I hope it's true.

And I don't mean to push you at all. I guess maybe one of the
ways that I would ask about how religious one is , is whether in
a crisis you really pray to something.

Yes, I do. I'm never surein fact, I say my prayers every
night. I really don't know for sure if there's somebody
listening, but it seems to help. Somehow, I feel that there's
somebody else in charge.

Riess: Well, yes, the alternative is the hardest.

Schawlow: There is a booklet's see, it's called Cosmos, Bios, Theos .
It was by [Henry] Margenau and [Roy Abraham] Varghese.
Professor Margenau, who had retired from Yale University, wrote
a number of people and sent them a questionnaire about
religion. I answered, and 1 have a page or so in that which I
can probably dig up for you. I think the copy is somewhere
around here. We can look later.

But I haven't gotten around like Charlie [Charles Townes]
has, giving talks about religion. I remember once there was a
wonderful minister filling in at this church in Ladera. He
asked me if I would like to preach a sermon some Sunday, during
the summer particularly, I think. I said, "Well, it reminds me
of the sign at the barber shop. It says, 'We have an
understanding with the bank: they don't cut hair and we don't
cash checks. ' "

Riess: [laughter] That's good. Actually, I would find that somewhat
disconcerting. After all, a role thing is very important
there, to maintain the ministerial role.

You said you felt your father had a kind of mathematical
ability?

Schawlow: Well, I mostly saw him on arithmetic. One of the horrible

things about that job was that every week they had to prepare
their accounts, and they had to list every single policy on a
great big sheet of paper, I don't know, maybe two and a half
feet square or something like that. And they were long
columns, and you'd have to move the policies from one week to
the other as they were paid up. Then they have to add up all
these columns, and the differences had to equal the amount of
money that they turned in as they moved from one week to the
next- -it was marked as paid up. So he had to do a lot of
addition.

When I was in high school I used to help on that sometimes,
and I think I got pretty good at addition. He knew something
about geometry, but we didn't discuss it very much. He could
always beat me at chessespecially if we bet even one cent, he
would beat me. But I didn't take chess very seriously. I got
a book and studied it some, but I have never taken games very
seriously.

He would 've made a poor engineer, I think, because he had
no feeling for mechanical things. My mother used to do any
repairs that had to be done around the house often in a way
that sort of shocked you really, because it was rough and

ready: whatever was at hand, she'd string things together with
it. I think she might 've made a better engineer. I think he
could 've become a theoretical engineer or a scientist, and it's
perhaps a pity that he didn't.

Riess: What other kinds of things do you remember doing with him?

Schawlow: Well, he was very busy, of course. We'd go for drives and

occasionally walkshe would drive us out in the country. We
did play chess some. And I don't really remember anything else
very much.

Riess: It sounds like he worked very hard. Maybe there was a sense
of, "Your father is working. Don't disturb him."

Schawlow: Well, he had to go out essentially every evening, because
that's when people were home. He had to make these
collections. He didn't have a lot of time.

Riess: Did your house have books, music? What was the ambience?

Schawlow: We did have a Victrola that somebody gave us at one time, a
windup one, and we had a few records, I think, that had come
with it. For a while somebody lent us a reed organ, and I
tried to take piano lessons and practice on that, but that was
hopeless, you can't play piano stuff on a reed organ. We even
had a piano that somebody lent to us for a while, but I don't
think we felt that we could afford to buy a piano. No, there
wasn't a lot of music around the house. Oh, we had the radio,
and of course, that was a wonderful thing, there was all kinds
of music on the radio.

I had asthma when I was a boy. We used to go to a farm in
the country for some weeks in the summer, but then I started
getting asthma very badly from an allergy to ragweed. They did
tests, and they gave me shots for it. Eventually, I outgrew
it. I think what happens isI've been told that the irritated
linings of the bronchial passages don't go away, but they get
bigger so there's room for the air to flow through.

But because of this asthma, somebody suggested I should
take singing lessons. And I did take singing lessons from a
very good teacher. She never told me that I really couldn't
sing. I had a good voice, but I couldn't carry a tune, really.
I just have a poor tonal memory.

I did sing for a while in an Anglican church boy's choir
[laughs] that's another of my religious variations. It was a
small church, not a big one. I think I had a nice boy's
soprano voice. It used to bother me that things didn't sound

right to me, but I couldn't tell what was wrong. She was very
good. One of her sons had a somewhat successful career as a
singer in the United States. The other one was an artist. She
was Mrs. Louise Tandy Murch, and she lived to be almost a
hundred. My sister sent me a newspaper clipping about her.
But I lost touch with her when we moved out to the suburbs. I
think the Depression was really beginning to bite, and my
parents said I had to stop the singing lessons. Well, it
didn't matter too much because I really wasn't much of a
singer.

Riess: And did that really help the asthma? Was the idea that you
learned a different kind of breathing? What was the point?

Schawlow: I don't know. I guess that you exercise your lungs and so on,
maybe build up lung capacity.

At that time, under Mrs. Murch' s influence, I thought there
was no music but classical. We didn't listen to an awful lot
of anything, to tell you the truth, but there was a lot of
light classical music on the radio in those days. I remember
there was a program on Sundays by Ernest Seitz who played the
piano, light classical stuff. He and Gene Lockhart, who later
became a successful movie actor, wrote "The World Is Waiting
for the Sunrise."

Early Interest in Engineering and Science it

Schawlow: There was a library branch within about a half a mile or so,
and particularly in the summer we'd go over there and get as
many books as they'd let us take out--I guess it was six or so
at a timeread through them and bring them back and get some
more. So I read a lot of books.

Riess: What were you reading?

Schawlow: I was interested in things concerned with engineering and
science.

Riess: We're talking about little Artie. Little Artie?

Schawlow: I was never called Artie. My family called me Bud, and they
still do. But yes, even then I had those interests. Once I
started to use a Meccano set, I started to read Meccano
magazine and that had stuff about building bridges and that
sort of thing. I was interested in radio, although I didn't
have any money to build anything much. I think I built a
crystal set. And then we also read a lot of books, oh, of

mythology- -The Iliad and The Odyssey, and some of the Norse
legends, too.

Riess: And adventures?

Schawlow: Yes. There were some good books. There was a series of books
about a Boy Scout named Roy Blakeley, I think. I don't know
what the kids get now, I don't see any such things. These were
good for, well, going on towards teenage. I read a lot of
Jules Verne.

One thing I didn't mention about the cultural background:
at home we had the Book of Knowledge. It was a wonderful
thing. It had summaries of a lot of famous stories, so I got
some idea of what they were about. I spent a lot of time
reading that.

Riess: How is that different from an encyclopedia?

Schawlow: It's not written as an encyclopedia. I don't remember how it's
arranged. Actually, I found a copy in a used book collection
and bought one, left it up in Paradise a couple of years ago,
but I haven't looked into it. Well, it was almost more like a
magazine, or collections of articles on various subjects and
stories. There were some stories, as I say, some summaries of
famous stories.

Riess: Was it a series?

Schawlow: Well, it came out all at one time, but it was a set of books.

Riess: Did you have an encyclopedia?

Schawlow: I don't think so, no. I don't think we had an encyclopedia.

Riess: What do you think: if you had been given a chemistry set
instead of a Meccano set, where would you be today?

Schawlow: Oh, goodness. I did play a little bit with chemistry sets at
one time or another, but they didn't really intrigue me so
much.

It was radio, really, that intrigued me, and I read a lot
of books about radio even starting then. And there were people
who had old radio magazines that I could get and read through
some of them, I think even when I was on Sackville Street--!
left at age eleven, but I'd finished grade school by then.

Riess: Let's go back to the grade school years. You were skipping
some grades in school.

12
Schawlow: Yes, I was. Until I met Miss Bray.

Riess: Were you head and shoulders above your classmates? Why did
they push you on so? Now they tend not to do that kind of
thing.

Schawlow: I don't know. I guess I could do anything that they put in
front of me, and I had a good memory at that time, I could
learn things fast.

I don't really know. I guess I was a lot better than most
of the others. One thing I do remember, and I think it was a
very good thing, when I went to the Model School I was a couple
of years younger than most of the others in the class, and it
was a selected group, too. I felt that some things I could do
better than them. Still, it kept me from getting a swelled
head, thinking I was smarter than everyone else.

I've known a number of scientists who apparently were the
boy genius all their life, and they're really pretty arrogant.
But I learned that there were other people that are pretty
good, too. I'm not very competitive; in fact, I think I'm
about the most uncompetitive person you ever saw. And I avoid
competitionprobably one of the reason I don't like games: I
don't like to lose and I don't like to see somebody else lose,
either. So I never really worried too much about what others
were doing, I just did what I was asked to dodidn't go much
beyond it, either.

Riess: I guess a lot of physicists and engineers have a love of radio
as the beginning of their life story.

Schawlow: It was so exciting, really. I remember when we got our first
radio it must have been about 1925 or 1926, and it was
battery-operatedall the kids on the block would come around
to listen to "Santa Claus' Adventures on the way from the North
Pole," sponsored by our local department store, Eaton's. Also,
the newspapers had articles every week on how to build radio
sets with circuit diagrams. There was a lot of excitement.

Riess: You were offered the means to make this thing.

Schawlow: It was wonderful. The radios were made out of standard parts,
and you could put together almost anything that was known then
out of standard parts. For a while, you could build things
cheaper than you could buy them. But then eventually they got
into mass production and it really wasn't possible to do it.
Well, people moved to the short waves, whereas the broadcast

band was pretty much standard factory items. People built
their own short wave sets, and I did too a little bit.

Riess: Can you remember struggling with the concept of radio waves, of
how they were was transmitted?

Schawlow: No, I can't remember struggling with it.

Riess: You understood it right away?

Schawlow: Either I understood it, or I didn't worry about it. [chuckle]

Riess: I'd sort of like to know.

Schawlow: I guess I understood something. [pauses] I may have gotten

something out of that Book of Knowledge about it; they may well
have had a section on radios and how they work. No, I don't
remember ever worrying about it. But my knowledge was not very
deep.

Riess: I'm interested in your general curiosity as a kid. For

instance, when you're out taking a ride with your father in the
car, and you see the telephone wires looping down the highway,
does that make you start to think about--?

Schawlow: It does more now than it did then. I remember, maybe twenty
years or so ago, I was in England taking a ride on the train.
It was an electric train, and I was thinking, "What a marvelous
thing it is: this invisible electricity flows through here and
moves this huge train." I guess I had a sense of wonder and
interest all along the way, but I learned it in little bits and
pieces.

Riess: You're saying that it was the sheer pleasure of building things
that was more appealing?

Schawlow: I think understanding things was more appealing, but then

building, too. I really wasn't very good at building because I
was very clumsy. And I didn't really have a lot of money to
spend on it, either. Building it and having something work,
and produce some music out of the air--that was pretty
exciting.

Riess: Dealing with what you describe as your clumsiness wasyou
obviously surmounted it.

Schawlow: Well, I got people to do things for me. [laughs]

Riess: Is that really true or is this just some kind of legend that
you have of yourself?

Schawlow: No, it's true. In fact, my students and technicians don't want
me to touch the equipment some of the time. I learned some
tricks to do things, finally. I realize the reason now why I
don't like mice on computers is that you have to position the
pointer, the cursor, exactly, and I find that hard to do. I
really find it hard to get that thing placed exactly where it's
supposed to go. I can do it, but it's not easy.

I don't think I ever passed in art class; however, they let
me through anyway. As I think I wrote down in that draft for a
biography, when I got to high school I had to choose between
either taking art and botany, or bookkeeping and typing. I
knew I couldn't pass art, so I took bookkeeping and typing
because I really am very clumsy.

Riess: That is a surprising anecdote to me, because you were obviously
smart, and I should think any school counselor would say you've
got to take botany because that's the academic track.

Schawlow: I don't think we had a school counselor then. I'm not sure
they'd been invented.

Riess: But it turned out to be a good thing to have taken typing.

Schawlow: Yes, it was good. I was all right. I'm not a great typist; I
can type fast, but not accurately. I think computers were
invented for me because I can make my mistakes and fix them.

Riess: I noted in your autobiography, when you were talking about
using your hands, that a psychologist was consulted. Why?

Schawlow: Did I say psychologist? It was some kind of a doctor.

Riess: [referring to pages of the autobiography] "Someone, I think it
was a psychologist, told my mother I would never make my living
by my hands . "

Schawlow: I see. Well, now I don't know. It might have been just a

medical doctor, but I guess she had noticed I was clumsy. When
I had this trouble with the teacher in the--I guess you'd call
it fifth grade, but it was junior third, they number them
junior and senior first, junior and senior second, and so on.

Riess: Please go back and tell that story, because it won't be on our
tape. After you'd skipped one grade and skipped another grade,
you landed in the hands of

Schawlow: this teacher [Miss Bray) , a woman who had liked my sister
very much, but somehow didn't like me, and claimed I was

stupid, and also claimed I liked throwing spitballs. I had to
ask my mother, "What's a spitball?" I really didn't know.

So my mother took me to a psychologist who gave me an I.Q.
test. And I hate to give you a number for printing--! can tell
youbut it came out as 152. As I say, I hate to put that down
in writing because I.Q. tests are very unreliable--! mean,
quantitatively: I might have gotten more one day, less another
day. Anyway, that's when she arranged for me to go to the
Normal Model School. I guess he suggested it, probably.

But as I say, the teacher had said I was stupidothers
hadn't thought so.

Riess: Yes!

Schawlow: I guess I can't be sure who it was who had suggested the
Meccano set.

Riess: You knew you wanted to be an engineer? Had you met an
engineer? Did you know what an engineer really did?

Schawlow: No. Well, I had read a lot of books about engineering, I mean
about the achievements of engineers, and I knew about building
bridges and highways, and all that sort of thing. But did I
know about the day-to-day work where they have to sit at the
drafting tables and draw complicated diagrams? No, I didn't
know about that .

I did meet one radio engineer, briefly, who was some friend
of a friend. And this man had a hard time. He got a
bachelor's degree in electrical engineering and couldn't get a
job. During the Depression, for a while he was winding coils
in a radio factory, strictly a technician's job. I don't know
what became of him later, but I knew that wasn't what engineers
were supposed to do. I thought they were supposed to invent
and design equipment.

Riess: This was a time of a great flowering of engineering, wasn't it?

Schawlow: Well, there was a lot of engineering going on. Of course,

engineering had really started in the mid-nineteenth century.
I mean, I read about the people who designed the railroads,
Isambard Kingdom Brunei, who built the Great Western Railway,
and some wonderful bridges, and also the first steamship for
running cable across the Atlantic. Much later, when we went to
England in the 1970s, I went to Bristol and saw one of the
bridges that he had built. I thought that was pretty wonderful
stuff.

Riess:

Electrical engineering, of course, that really didn't begin
with Faraday. I mean Faraday's invention of the dynamo was
necessary, but it took a while before it really became an
engineering thing, not science. But it waswell, electricity
and Edison and so on, and electric light distribution things,
those were before the twentieth century, I think. They were
pretty much underway.

Did you imagine yourself being a kind of master builder along
these lines?

Schawlow: I could imagine myself being a master builder, but I really
couldn't have done it.

Riess: Had you heard of physics?

Schawlow: Not very much; I guess I'd heard of it, yes. I was interested
in electricity, mechanics, and so on, so I guess I knew that
that was the sort of thing that physics dealt with. I know not
everybody had. I remember once, during the war-time years I
think it was, 1 met the mother of one of my friends and I
mentioned that I was studying physics. She didn't know what
that was, thought it had something to do with medicine.

High School. Vaughan Road Collegiate Institute

Riess: I think we're at the point where you made the move to the other
neighborhood.

Schawlow: Yes. I went to high school there, yes. And I was, of course,
the youngest one in my class, but I didn't have too much
trouble with the coursework. I don't know, my sister seemed to
think I just breezed through it, but I felt I was working. I
always had a lot of things to occupy me: I was still interested
in radio and beginning to build a shortwave set, a two-tube
shortwave set, things like that.

Riess: Did you always do that from magazines and kits, or did you have
some mentor who helped you?

Schawlow: Not kits. Mostly magazines. When I was about mid-way through
high school I met a man named William James Crittle. He was a
radio technician, really. He had been gassed in World War I
and was living on his pension pretty much. He was a very
enthusiastic radio amateur. I used to go over and talk with
him after school quite often. And, as I say, he wasn't really
working. I learned some things from him, but at other times I

was shocked by his ignorance of fundamentals. I had mentioned
something about the crest of a radio wave, and he thought that
was up at the top of the atmosphere. Whereas the crest is the
place where the electric field is the maximum of the
electromagnetic wave.

Then I tried to build a super heterodyne radio, and it
didn't work, so he took it apart and rebuilt it for me. So I
never really built a very big radio set; two tubes was as about
as far as 1 succeeded.

Riess:

Schawlow:

You took Latin, French, and German,
languages?

Were you good in

Riess:

Schawlow:

I don't know. I had no trouble, and I was always near the top
of the class, but I never learned to speak any languageswell,
they didn't really try to teach you to speak. I'm not like
these kind of people who pick up another language every year,
but I never had any trouble with it. I always could do very
well with what we were asked to do. I tended to do that with
my coursework; whatever I was asked to do, I did. But I didn't
go beyond it much.

Except in the things that you loved? The physics and
chemistry?

Well, the physics and chemistry, I read a lot around them, but
I didn't really try to go deeper into the particular things
that we were being told to study. In the third year of high
school we started to take a physics course, from a man named
Harston who obviously didn't know very much. He was also the
part-time physical training instructor. It was all right, but
not very stimulating. The fourth year, I think we took
chemistry. And then the fifth year, chemistry and physics.

Those last three were from a man named Robinson, C.W.T.
Robinson, who was known to everybody as "Speedy," because he
had a rather slow way of talking- -although amazingly, he had
been a fighter pilot in World War I. We had five years of high
school, thirteen grades in Canada. I think they still do, but
I really don't know why because the Americans, at least those
that come to Stanford, are just as well-prepared as we ever
were. But perhaps I couldn't have taken so many languages if
it hadn't been for that. Anyway, in the last year he just told
me to do all the problems in the book at my own pace. That was
pretty good, so I learned everything that was in that textbook;
but I didn't try to get another, more advanced textbook or
anything like that. I sort of read the popular accounts of
what was going on.

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

In high school mathematics I was at the top of the class,
could do very well. Got to universityit was much tougher.
There were people there who really had mathematical talent--!
had to struggle. And then when we got on toward the fourth
year, the last year of college--! don't know, it's fortunate
that we didn't finish the year, because the war was on and they
put us to work teaching classes--! found that physics was
getting very mathematical, and I didn't like it.

I liked to visualize things, and I think that's one of my
abilitiesalthough I haven't got a good eye. I always tell
people that I think in terms of fuzzy pictures, but I'm pretty
good at that. I sort of train myself to think, "What's the
essence of this? What's this all about?" It got sort of
discouraging as the physics became more a matter of equations
and formulas .

But then after I graduated I came across this wonderful
book by Karl Darrow I think he called it An Introduction to
Contemporary Physics [Van Nostrand, 1926]. Karl was a nephew
of the famous lawyer Clarence Darrow, and for many years he was
the secretary of the American Physical Society. Anyway, this
book described the basic experiments on which modern physics
was based, what they did and what they found, and that was the
kind of physics I likednot writing out equations.

That really didn't happen until the end of college?

Yes. Well, it didn't really get that bad until then. I don't
know, it seemed like physics, a lot of it was with concepts and
learning facts about things, how things worked. But then they
sort of get into the more formal mathematical treatment and I
didn't like that.

Physics wasn't sold to you as the underlying principles of
everything?

Well, I guess it really wasn't sold to me.
Sorry, I didn't really mean that.

I don't know. Well, physics certainly seemed already by then
to be the basic laws of the way things worked. But for
instance, we didn't have transistors, or semiconductor devices,
and so it wasn't really fully appreciated the way physics,
solid state physics, would open up a whole world of devices and
so on. It certainly was the way that structures, like bridges,
had to be designed to withstand the stresses--

Some Beliefs, and Some Disbeliefs ##

Riess: [looking at Cosmos, Bios. Theos] Why are people so fond of

asking scientists for the answer? After all, they don't ask
art historians for the answer.

Schawlow: Well, the man who edited that book, Cosmos, Bios, Theos, was a
physicist, and so perhaps that's why he thought of asking
scientists.

Riess: But you know it's more than that, too.

Schawlow: Yes. Yes, I guess so. I think that you confront the universe
and perhaps learn something about it that wasn't known. And
there's, of course, a long history of complaints that science
conflicts with religion. I don't think it should. But on the
other hand, religion has very often tried to explain the things
that we don't understand, and then science comes along and
explains them, and they feel, "Oh, boy, God's been moved out of
that part of the universe, too."

You know, centuries ago everything seemed magic, we didn't
understand anything much. But as we have science we do
understand a lot more in a straightforward way. Still, there's
so much we don't understand that I think there's an awful lot
of room for religioncertainly a guide for ethics. As I think
I said a while ago, the world is just so wonderful that I can't
imagine it was just having come by pure chance.

Riess: When you say that, "The world is so wonderful," what do you
picture right away when you say "the world is wonderful"?

Schawlow: I think the beauty of the trees and flowers and so on, and the
fact that people can exist and have produced such marvelous
artistic creations, in sculpture, painting, and music. Of
course people ask, If God exists, why does he allow such
terrible things to happen? And there certainly is a lot of
evil in the world- -and a lot of good, too. In every family,
usually, the parents provide love for the children, at least in
most families, and that's a wonderful thing.

Riess: What do you think about afterlife?

Schawlow: I don't know what to think. As I've mentioned even to Charlie,
I don't see any place in this universe for a heaven. We've
explored it pretty thoroughly, so that if there is any, it has
to be very different from anything that we can imagine here.
It's not tucked just above the clouds, there, we're sure of
that. On the other hand, if you think that the whole human

being is encoded in a tiny bit of DNA, which is so small that
you couldn't see it without a microscope, then perhaps the
essence of a human being is somehow transmitted to a different
sort of universe.

You know, in some ways, I think that the soul, such as it
is, is sort of the operating system of the human. It's more
software than hardware, in the modern metaphor. Of course,
that metaphor may be thoroughly dated in a little while. But
you know, there were some people who, I guess, were religious
skeptics. They said, "Well, let's weigh the body as the person
dies and see if the soul is escaping." I think that doesn't
make any sense.

But unfortunately, as you get older it gets harder to feel
confident that there's an afterlife, or that it's anything at
all like life. Perhaps if I spent more time in church I would
feel stronger. One of my daughters has gotten very
passionately fundamentalist and would like me to become so,
too, but I don't think it's in me.

I would think it would

Riess: Why does it change as you get older?
work the other way.

Schawlow: It's getting closer.

My mother, too. She sort of lost her faith as she got
older. I don't know, really. I guess I'm just honestly saying
that I do not know, and I don't think that anybody can know.
On the other hand, unless the story of the resurrection is a
total lieand it seems to be well attestedthen there are
some things that are beyond our ken.

And I don't understand our daughter, this one I mentioned
who feels that salvation comes from the sacrifice of Jesus.
Well, it's an interesting biblical concept of sacrifice, which
is not really a modern concept at all: I mean, why you have to
sacrifice something to get a good end, I don't know. On the
other hand, if you had to have Jesus die and then be
resurrected, that certainly shows you something that you don't
get out of the books. Maybe I'll eventually be able to accept
the concept.

One of the things that I got, a piece of software, is a
Bible search program. I looked up the word "faith," and it
hardly occurs at all in the Old Testament!

As far as I understand the Old Testament--! 'm not a
biblical scholar, but I've been in a lot of church services and

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

I've heard a lot--I think that some of the Jewish people
believed that there were other gods, but their god was the
supreme one. I don't think that they really believed that the
other ones didn't exist. I don't knowbut at least you could
read it that way, I think. But there certainly are some
strange things. The Bible, of course, is a wonderful guide to

human behavior, what works and what doesn't work.
a variety of things there.

There ' s such

In church a few weeks ago the minister was discussing the
story of Abraham and Isaac, where he was ready to sacrifice his
only son. That's a strange story. In the end, I gather God
said to him, "Now I know I can trust you" or something like
that.

That's about faith, I guess.
I guess so.

I'm not the person to give you a good religious education,
because I just sort of learned. I think I have one principle
in doing science: start off believing everything. Because
otherwise, I've seen people who are skeptical about everything
new, and they don't believe anything, and they miss the boat.
But on the other hand, you can question anything. You don't
question everything, because then you're just a crackpot, but
you can question anything. And so, I guess I tend to have that
attitude toward religion. I don't know.

How do you figure out which thing to question?
question in science.

That's the

Yes. Partly instinct and partly a matter of seeing what
doesn't make sense. If things don't fit together, then you try
and see what's missing.

I spent some time with a book that's been much discussed and
reviewed, called The End of Science [by John Horgan, Addison-
Wesley Press, 1996].

Ooh! What nonsenseabsolute nonsense. I haven't read the
book, but I read the reviews of it and I think it is nonsense.
First of all, I gather it acts as if particle physics is all
that there is, and

It does. And cosmology at least in terms of your fields.
Yes, and those are not my fields at all.

Riess:

I think there are some wonderful questions in atomic
physics and condensed matter physics. I'm fascinated now by
the questions of nonlocality, where in quantum mechanics things
don't seem to be anywhere until you measure them. So you get
correlations between distant places more quickly if they start
out correlated, and say, two particles move apart in opposite
direction- -when you measure them, the measurement on one
affects what you can measure on the other one. It's considered
to be instantaneous, but there isn't really proof of that. In
fact, I'm trying to look to see what has been measured and what
could be measured. So I think the fundamental questions of
quantum mechanics and its interpretation are far from finished.

The author is provocative. He does quote [Hans] Bethe as
saying that important discoveries will continue in solid state
physics, but that there are no exciting, big discoveries left.

Schawlow: Depends what excites you.

I've seen particle physics develop kind of as a spectator;
it really didn't exist when I was a student. All we had was
the proton and the neutron and the electron. Now they have
this whole zoo of particles; they have more particles to
explain things than the ancient astronomers had epicycles.

Riess: Physics can be a kind of playground for popularizing writers,
and for religious writers too.

Schawlow: Anybody's free to speculate anything they want, but

fortunately, nature has provided us with a great analog
computer, experiment, which will tell us how to solve our
equations.

I have read several semi-popular books on the
interpretation of quantum mechanics lately. The religious
speculations, I just don't see how they can tell me anything
that I don't know. But I may be wrong, there.

Riess: Okay, well, let's go back to

Schawlow: Actually, let me say one more thing about religion. There are
enormously different cults and religious sects, and I think
it's not unreasonable, because I think God--if he's as
wonderful as we believe- -is also very complex, and that
different people have to see him differently. Of course, like
the blind man and the elephant story. But you can't expect a
peasant and a philosopher to have the same picture of God. I
think God is big enough to cover them all, even for science
writersthey can have their picture of God.

Riess: And even if they're trying to prove that he's not there, that
means that they're concerned about him.

Schawlow: I don't think they'll ever prove that, any more than you can
prove existence. I think we just have to learn to live with
uncertainty, and you sort of place your bets on what you think
is most reasonable, which is where I come down. Maybe I'm
wrongcertainly the Bible complains about people of little
faith.

Riess: Is the Bible that is in your computer program the King James
version?

Schawlow: Yes. You can get other versions, but I have the King James
version.

Riess: At least you get good writing.

Schawlow: Marvelous. Incredibly beautiful writing.

Entering College. University of Toronto

Riess: To the extent that I know you through your autobiography, I
think I've let you leap too far forward.

We were getting from high school into college, and the
decisions that were involved there, and the choice of subjects
that you had. You graduated young from high school.

Schawlow: Yes. I was just sixteen.

Riess: What were the possibilities, in terms of higher education, in
Toronto?

Schawlow: Well, there was one university, and as I say, because of money
we couldn't even think of going anywhere else. In fact, if we
could get into the university, that was going to strain all our
resources.

If I hadn't been able to get into the university I would
probably have tried to become some kind of a technician, a
radio technician or something like that. I don't know- -there
are schools that teach that, or you can learn it by experience.
But, as I say, one didn't think of going to places like MIT.
Either you got into the university or you didn't.

Riess:
Schawlow:

Riess:

Schawlow:

I think I wanted to get into the university, and probably
thought I would end up teaching high school. It was sort of
the thing that I could imagine. I don't think anybody I knew,
except doctors or dentists or teachers, had ever gone to
college. People who lived around us hadn't. And so I really
didn't have much of an idea what it was like.

They have these big formal exams at the end of the last
year in high school, which are given by the provincial
department of education. They occupy several weeks in June. I
thought, "Well, maybe I'm not good enough to get a
scholarship," because there are all these schools where they
have Ph.D.s for teachers, and so on, like Harbord and
University of Toronto Schools, "but I'll see what I can do."
Vaughan Road Collegiate was just ten years old, and nobody from
there had ever won a science scholarship.

It was 1937 and that was the year of the coronation of King
George VI, and there was a possibility that I could have gone
with the Boy Scout group to that coronation, but my parents
wisely decided that I should stay and take the exams. So I
did. When the results were announced in Septemberthey
appeared in the newspapers, that's where you learned about
them--I found that I'd gotten a scholarship for mathematics and
physics. I knew I wouldn't get one for engineering because
there were no scholarships for engineering at that time.

The University of Toronto was not free to the populace?

It was $125 a year, which doesn't seem like much money; even if
you give it a factor of twenty for inflation, it would still be
only $2500, which is not very much. But these were Depression
days, and my father had two children. I think even with the
scholarships it was a stretch, and he had to borrow money,
though he didn't talk about that. So, $125 a year certainly
doesn't seem like much. Before I graduated it went up to $175,
but the scholarship covered that. And now I'm sure they're up
in the thousands, though not like Stanford or Harvard.

You said something, back there, about not having any Ph.D.s to
teach you. But you went to the top high school in Toronto,
didn't you?

No, no, no. It was just the one that was near us. It was a
good high school on the whole, but not a great high school. It
was the Vaughan Road Collegiate Institute- -the "collegiate
institute" meant that the heads of each department had to be
qualified as specialists in a subject, like in French or
English or whatever, so they had certain standards. I really
had wanted to go to the University of Toronto school which was
affiliated with the university. And that's where a lot of

people from Model School went, but again, my parents felt they
couldn't afford it, so I went to Vaughan Road. They covered
the material that was described in the course, in the
textbooks, but they didn't go beyond that; whereas, I think
some of these other schools did give more advanced preparation.
However, the exams were based on what was in the course, and I
knew that thoroughly.

Riess: About the decision of which part of the University of Toronto
to attend--! don't understand how the University of Toronto
works .

Schawlow: They had what they called honor courses. It was specialized
right from the beginning. I think my scholarship was for
mathematics and physics, as I'd gotten high grades in that. I
don't remember whether I had to specify that before then, maybe
I did. I remember I applied to Victoria College, which
happened to be affiliated with the United Church of Canada, but
I didn't know that. I asked some teachers and they suggested
Victoria College. You had to choose one.

Riess: This is like the British system of a university having
colleges .

Schawlow: Yes. Colleges had dormitories and residences, and they had
some college life in which I didn't really share because I
lived at home and commuted by streetcar. In fact, I only took
one course each year, I think, at the college. You had to take
some sort of cultural subject that you would take in your
college. But the main course was mathematics and physics;
except for this one cultural subject, that's all you studied-
mathematics, physics, and chemistry. And then after the second
year, I think, it branched into physics and chemistry, or
astronomy, or an actuarial science. Mathematics had an
actuarial science specialty, and many of the top actuaries in
the continent's big life insurance companies had graduated from
there. We took courses in actuarial science the first and
second year.

Riess: Was that in some way like statistics?

Schawlow: Well, yes, it's calculating probabilities. It's taking the

life tables, for instance, life expectancies, and calculating
how much something is worth based on life expectancy.

Riess: Did this have any general application that you can think of?

Schawlow: No, I don't think so. It was kind of fascinating because it
was a lot of talking about what did you really mean here and

formulating the equations that I found attractive, but I felt I
never really quite got the hang of it to do it easily.

Riess: Did talk to your father about it? It was sort of in his line.

Schawlow: Well, not really. This is how the insurance companies would
set their rates, you know, by taking the probabilities that a
person would live so long. It's a strange subject.

I took a terrible chemistry course--! may have mentioned
that. This old Englishman named Kenrick taught it. He was the
head of the chemistry department, but he hadn't learned
anything since 1900, I think. He didn't believe in atoms. He
only believed in chemicals, and he talked about a fictive
constituent called "hydrogenion"--all in one word, instead of
talking about hydrogen ions. Really, what chemistry I learned
in high school is about all I learned.

Riess: You said you had good memories of the physics labs.

Schawlow: I enjoyed those. We had a good physics teacher for our first

year. He was also about the same age as Kenrick. He graduated
from Cambridge around 1905, and he'd written a number of
textbooks, but had not done a lot of original research. But he
worked hard at preparing problems every week and writing up
solutions to these problems for us. He also supervised the
lab, with some assistance. He was a very good lecturer--f airly
dramatic style and a lot of fun.

We had a wonderful calculus teacher, Samuel Beatty, who
later was dean of the faculty of arts and later chancellor of
the university. He made things very clear and interesting.
Some of the othersmost of the other mathematics professors
that I encountered were not so good as teachers, but then,
perhaps it was because my ability was lacking. But I got
through all right: in the first year, I was third in the
mathematics and physics course out of about fifty students,
something like that; in second year and third year, I was
first. By third year, of course, we'd split off into physics,
but I was top of the class before they split off.

I felt I had to work awfully hard.
Riess: You said you're not competitive. I don't understand.

Schawlow: I wasn't. But I was scared that I'd lose my scholarship if I

didn't get first class honors. And I would have. That was all
I really was worried about. Now, looking back, okay, I can be
pleased that I was at the top of the class, but the main thing

was that I kept my scholarship. No, I didn't feel I was trying
to beat out somebody particularly.

Riess: Was there an opportunity to have some individual time with any
of these people you respected?

Schawlow: No, not really. We could go 'round and ask them a question if
we needed to.

Riess: Were you learning a lot out of books?

Schawlow: Yes. I guess I was still reading some books about technology
and science, sort of popular books about it. But my feeling
around the courses at the university was that in high school, I
felt I could learn everything that was taught, but in college,
I knew I couldn't, so I just had to try and decide which was
most important, and try and make sure I learned that well. It
was really quite difficult. I felt I had to work pretty hard.

Physics in the Prewar and War Years

Riess: Charles Townes describes--! love the picture, and maybe I've
elaborated on itsitting on a rock by a stream reading about
special relativity. 1

Schawlow: [laughs] I heard that he took a physics textbook with him to
the circus once. That's what his sister told me.

Riess:

Schawlow:

Riess:

When were you introduced to special relativity?
remember struggling with it?

Do you

I think we had a course on it. Yes, we must have had that,
probably around the third or fourth year. I found it sort of
interesting, but not thrilling. I don't know. I guess I could
manipulate the equations as I needed it. I've never had the
occasion to use it since then, and I'm not really fluent with
relativity.

When you say that, I guess I almost can't believe it because I
think of science as a pyramid.

'Charles Hard Townes, A Life in Physics: Bell Telephone Laboratories
and World War II; Columbia University and the Laser; MIT and Government
Service; California and Research In Astrophysics, Regional Oral History
Office of The Bancroft Library, UC Berkeley, 1994.

Schawlow: Well, it's a number of pyramids, I think. Relativity does come
into atomic physics, but sort of in predigested form. I mean,
there are people who have applied relativity to the motion of
electrons and atoms. They obtain certain results such as the
atomic spin-orbit coupling depends on relativity. But I
haven't designed space ships or accelerated particles to
relativistic speeds, so I just really haven't had much use for
it. Thermodynamics is the same way. We took a course in
thermodynamics, but I've never used it. It's a fact that
actually, the old Tower of Babel is there; there are a lot of
different branches of physics, and unfortunately, people who
write books like The End of Science don't understand what we're
doing, and vice versa.

Riess: You mean by selecting particle physics as the essence of
physics .

Schawlow: Yes. I see how it happened all right. Atomic physics was the
way to go in the twenties and it opened the door to quantum
mechanics and that, of course, led to a lot of other things.
But then you started looking at the fine details of the atom,
like the nucleus, and that led you into nuclear physics. Then
they started to get accelerators and so then they

Schawlow: --started getting new particles, and the whole field of

particle physics began. So they felt that they were leading to
an essential simplicity.

I haven't followed it closely because it just doesn't seem
that they would have anything to offer me. Culturally, it's
kind of interesting, but it deals with things in a very
artificial sort of way, at very high energies, and you need
huge machines to create them, and they only last for a
trillionth of a second or something like that. What they do is
they sort of follow spectroscopy and order things in patterns
that are, really, in essence, based on atomic physicsalthough
they've had to make some modifications which are fairly
profound.

Riess: You say they follow spectroscopy?

Schawlow: Yes, they do, in sorting out thingsangular momentum,
selection rules, so onthey follow the ideas of atomic
spectroscopy. Of course, it's different because these things
are also strongly interacting. But it seems to be a field in
itself that doesn't lead anywhere else as far as I can see.

Riess: And yet, you think it's overly identified as the calling for
physics.

Schawlow: Yes. I do. I think there are people who think that we know
the laws of quantum mechanics and everything's understood in
principle in the atomic everyday realm. Well, it may be
understood in principle, but it's certainly not understood in
many respects.

Riess: The Tower of Babel image is the other extreme, sounds totally
out of control and zipping off in all directions.

Schawlow: I think so. This supercollider they wanted to build- -some

physicists, like Phil Anderson, actually came out against it.
He's a solid state theorist. I didn't do anything, one way or
the other, but I think there were a lot of physicists who felt
that's just not the kind of physics we know.

I understand what this man [Horgan] is talking about, his
book. The theories that they have now, there are a lot of wild
theories: the theories of everything- -they call these string
theorythat seem to require experimental facilities far beyond
anything that we can ever hope to build, and that's certainly a
dead end. I heard a talk that said that physics may be
becoming like the cathedrals of the Middle Ages, which took
centuries to build, and you can't do these problems in one
generation.

Riess: One thing was interesting to me: he said science has existed as
an activity for only a few hundred years, and yet people think
of it as being a permanent feature of existence. But, in fact,
it may not be.

Schawlow: It may not be. Of course, even existence may not be permanent.
There 're so many ways that people can destroy our world, it's
really very upsetting. With missiles and atomic bombs, I can't
think but sooner or later there'll be an accident, or a
terrorist or a rogue nation will set off some of these things,
and we may think it's another big countryit ' s horrible. When
the United States and the Soviet Union were confronting each
other, I could imagine that if Libya had gotten hold of an
atomic bomb and set it off, we might think it was the Russians.

Riess: Okay, I waylaid you by talking about special relativity. But
were you beginning to zero in on what you wanted to do in
physics?

Schawlow: No. All I would really study was radio. I did a lot of

reading about radio, radio technology reallynot really deep
science. No, what I wanted to dowell, like everybody else I

Riess:

Schawlow:

Riess:
Schawlow:

Riess:
Schawlow:
Riess:
Schawlow:

thought atomic and
After I came back,
would really have
run down by then;
of the departments
balance the budget
up their research
but they never got

nuclear physics were the exciting things.

after the war, nuclear physics was what I
liked to have done. But Toronto was pretty
they had suffered during the Depression. All

were asked to give up something to help

and the head of the physics department gave
funds. It was supposed to be for one year,

it back.

So there was very little money to do anything. They didn't
have an accelerator. And the system of government support of
science hadn't been developed yet in Canada. You had to make
do with what was available. Well, the nearest thing to nuclear
physics was studying the properties of atomic nuclei by
details, hyperfine structures it's called, in the spectra of
atoms. There was a pretty good man in that field, Malcolm
Crawford. So that's what I did. It isn't what I would 've most
preferred, but I sort of have always taken advantage of the
opportunities that present themselves. I haven't been a good
planner, I just see what's available.

Please go back and talk about the war period,
chance that you would have been drafted?

Was there any

Yes, I could 've been drafted by two countries. I had to
register in both Canada and the United States, because I was
still an American citizen but residing in Canada. But the
Canadians felt I wasn't a healthy enough specimen.

You still had the asthma?

Well, I had a stomach upset at that time. Strangely enough,
the doctor who examined me at the draft place was the same one
who had been treating it. Anyway, they turned me down.

Was that upsetting?

That I was turned down? No, I didn't want to go.

What was your attitude? Was that a war you wanted to fight?

I'm not a fighter. I felt it was a just war, all right, and it
would be horrible if Hitler won it, but I didn't see myself
being a fighter. I sort of was willing to be on the sidelines
as long as I was doing something that was helpful. What I was
doing was needed and required my knowledge. Later, the
Americans wanted to draft me, but by that time, I was working
for this Research Enterprises Limited radar factory. They had
a representative in Washington who somehow got that stopped.

31
Riess: Were you political during college?

Schawlow: No. I'm just amazed thatwell, Canada had a liberal

government, and had had one for quite a few years. I guess I
felt that was sort of a good government. The word "liberal"
wasn't considered as obnoxious as the Republicans seem to think
it is nowadays. Well, I couldn't vote. I know we had one
student who was a committed communist, and I could not
understand that. We'd already seen in our newspapers articles
about the show trials and concentration camps in Russiathis
was no secret. I just couldn't understand how anybody could be
a communist. But I wasn't active at all. I didn't have any
time to do anything but study and play with radio a bit.

Radio. Scouting, and Jazz Music

Riess:

Schawlow:

Riess:
Schawlow:
Riess:
Schawlow:

Riess:
Schawlow:

And how about your summers?
jobs?

Did you support yourself with

No, jobs were very scarce. The only time that I found a job
was when a fellow student got me working for a couple of weeks
in a factory that was making Christmas cards by silk screen
printing. And I was helping there, most of the time cleaning
Christmas cards: if they got a blob of paint you'd take a sharp
knife and scrape it off. It paid twenty cents an hour.

However in one year, I believe between the third and fourth
year, I was allowed to serve as a volunteer in the radio lab at
the physics department.

That was during the year or in the summer?

In the summer.

It was a radio station?

No. It was mostly a teaching lab. I don't remember that we
really did very much, but I could learn to use some of the test
equipment.

You mentioned the Boy Scouts,
your life?

Was that an important part of

Yes, it was fairly important for a while. I'm not really an
outdoor person: I went camping one year, didn't like it much,
but survived it. They were nice kids in Boy Scouts. We got
along. One in particular, Bill Michael, became a close friend.

I wanted to be a radio amateur, you know, but I couldn't
qualify because you had to be a British subject to get a
license. So I couldn't get a license; though I passed the
test, I found I couldn't get it. But he had got an amateur
radio station and I used to go down there sometime and help him
out.

Riess: What could he do with that?

Schawlow: Well, it was Morse code. He would transmit and talk to other
stations, other amateurs. Nothing terribly serious. But I
thought it was very exciting to hear somebody from across the
world or across the country.

Yes, shortwave radio was exciting. I mentioned that I
built this two-tube radio set when I was in high school. I
used to come home at noon, because it was only a few hundred
yards away- -some times the periods were staggered so I'd have a
long lunch hourand I would tune up the radio and listen, and
you'd get places from all over the world coming in. Quite
amazing on amateur bands. I think one day I got ten different
countries. That was exciting.

Riess: Tell me what a two-tube radio is.

Schawlow: A so-called regenerative receiver which is on the verge of

oscillating, one tube, they can be quite sensitive, and so you
adjust them so they're not quite oscillating. The second tube
was just an audio amplifier to make the sound louder.

I learned, although I'm clumsy, how to tune that thing
finely. By putting my thumb and first finger on the knob and
sort of balancing one against the otheryou push a little bit
--I could adjust it quite finely, which I had to do to get
anything to work.

Riess: Did that make you want to make a better whatever-it-was?

Schawlow: Yes, it would 've been nice to do that, and I did try to build
this super heterodyne. As I say, I didn't get it working.
This was about a five tube radio, I think, something like that.
And I made some mistakes in the connections. I would 've liked
to have a transmitter, too, an amateur radio station, and talk
to people around the world, but that wasn't to be.

The Boy Scouts--! got a lot of these proficiency badges I
think they called them. I became a King's Scout, which is the
highest rank, and got the gold cord, which you get if you have
twenty-one badges or something like thatwhich is way beyond
what anybody else in the troop was doing. But it was easy for

Riess:
Schawlow:

Riess:
Schawlow:
Riess:
Schawlow:

me to learn a subject and qualify for a badge. I got some
weird things, even bookbinderalthough my bookbinding was sort
of barely passing.

But what about the Eagle Scout rank?

Didn't have that. King's Scout in Canada is about equivalent
to the Eagle Scout in the United States, I think. That was the
highest rank there.

And when were you introduced to jazz?
years?

Was it in your college

Yes. During my college years I had that radio, that super
heterodyne, and I used to listen to it, and about the only
thing that I found that I enjoyed was the swing music. There
were a few other people I knew that knew a little bit more than
I did about it. And there was a program, an afternoon swing
session, that played some real jazz.

Where was it broadcast from?

It was from Hamilton, I think, which is about forty miles away
from Toronto. Toronto, of course, didn't have very many black
people. There wasn't a black district. It had tight liquor
laws, so there weren't a lot of nightclubs. There were a few
ballrooms where visiting bands would play, but I didn't go to
those until later.

But I started listening to the radio, and liked some of the
swing bands that I heard. So I went to the music library to
see if I could learn something about swing music, and there
weren't any books on swing. But there were a couple of books
on jazz, and I read those. And books came out around that
time. So then I started to explore, look for people like Louis
Armstrong and Bix Beiderbecke, trying to find their records.
There were a few of them.

Did you start buying them then?

I started buying records in August, 1939.

How do you remember August?

[laughs] I can almost give you the date. One friend I'd met
through the Meccano club had a place out in the country, near
Toronto. I went out there for a night or so to observe the
meteor shower, the Perseid meteor shower, which is just about
the middle of August, and on the way back I had to change buses
at the corner of Bay and Bloor, and there was the Promenade

Music Center, and I went in and bought a copy of Artie Shaw's
"Back Bay Shuffle," which is still a great record.

It was interesting that the records on the popular jazz
labels like Bluebird and Decca were thirty-five cents. And
then the war started just a few weeks later. This was in 1939.
Canada got into it the beginning of September, 1939. The price
immediately went up to fifty cents. Of course, they were right
to do that because shellac came mostly from India, and shipping
was very difficult. So they knew there was going to be a
shortage of materials.

Mostly I bought records from the juke box stores. These
companies, any new records that came out they put them on the
juke boxes, and if they weren't getting a lot of plays they'd
put them out and sell them. I think they were fifteen cents at
first, later maybe a quarter. And you'd have to sift through
whole piles of records, whole tables covered with piles of
records, and learn to read upsidedown and sideways that way.

Riess: Were they out of their jackets?

Schawlow: They had just paper jackets where you could read the label.

They didn't have fancy covers like LPs do. So I bought quite a
few records that way over the next few years.

Riess: And you had a record player that was your parents?

Schawlow: Actually, at first I borrowed a windup record player from a

fellow during the winterno, my parents didn't have onethen
my father bought me one. Someone, I think one of his
customers, had this thing for five dollars. It was just the
turntable and pickup head, which by modern standards was
enormously heavy. It was amusing: when it was a synchronous
motor you'd start by spinning it, and you could start it
backward to play things backward. I connected that to my
radio, you see, it played through it, so I played these in my
bedroom.

Riess: Did you have to invent something to connect it to the radio?
Or could you just go and buy a gizmo?

Schawlow: I think it took a little circuitry. I don't remember, really.
It wasn't a big problem. I knew enough about how the radio
worked to know where to connect it.

Riess: Well, that's a great memory, isn't it?

Schawlow: It was fun, yes. My sister was interested in jazz, too, so we
shared records, she would buy some. Over the years we
accumulated a number of records . I remember once one of my
college classmates came over to my house and we played all the
records I had. That was the last time I ever played all the
records I had because I had too many to play.

Riess: How much music was on a side? How much time?

Schawlow: Three minutes, typically. Actually, I think there's a lot to
be said for that. It imposes some discipline on the musicians
--that was what a 78 rpm, ten-inch record would do. I think
since LPs came along a lot of the more modern musicians get
awfully long-winded and I think they ramble on for half an hour
or so, whereas the great musicians of the swing and jazz era
could say it all in a chorus or so.

Riess: Do you have now, on CDs, rerecordings of these collections?

Schawlow: I haven't everything, but I have a lot of them, yes. And I
will probably build up more of those, too. Not everything I
bought was good. In those days at least when you got one
record that was a big event, and you'd play it over and over,
really get to know it. You could even sort of pick out a
particular passage because they [the grooves] were pretty
spread out; you could put the needle down about the right
place. Now, I really feel bad, I buy a CD, there's an hour's
time on it, and I never really get to know it as well as I knew
some of those old ones.

Riess: It's the first thing you've described that would really take up
the kind of time that you had been giving to your studies.

Schawlow: Of course, not being a musician, I like to play music in the
background while I'm working.

Riess: Oh. But you couldn't do that with three-minute music.

Schawlow: Yes, that's right. Couldn't do it very well--yes, changing the
record. But the radio, when there was some jazz on, I didn't
have to concentrate on it.

Riess: And you did play an instrument also, didn't you?

Schawlow: Well, during the war when my studies were interrupted, I
decided I would try to learn to play clarinet. I really
admired people like Artie Shaw, Benny Goodman, and Irving
Fazola.

Riess:

I don't know that last name--Fazola?

Schawlow: Yes. He played, at that time, with the Bob Crosby Band. And
one of the things that I'm very pleased with now is that
there's a company in England that's gradually reissuing all of
Bob Crosby's records. Very graduallyone comes out about
every six months or so per year. But I've got a lot of those.
And Fazola's just as wonderful as I remembered. He had the
most beautiful tone of any clarinetist, jazz or classicalI'll
play you a sample if you like.

Anyway, I admired them. So I went to this teacher who
offered to lend me a clarinet, to try it out. Well, I tried
it, I thought it'd be nice, and I managed to buy one.
Instruments were scarce then, and I bought a clarinet that was
probably a mistake. It was a metal clarinet, but it was made
by the Selmer Company, which is a very good company. It was a
so-called full Boehm, which had extra keys so that a real
musician could play A clarinet parts on it as well as the B-
flat part. It made it somewhat easier.

I enjoyed trying to play it, but it became apparent that I
wasn't going to be a great musician. However, I got far along
enough that I could play with a few other amateurs --we had a
little jazz band.

Riess: Where did you find them?

Schawlow: It's hard to remember just exactly what came first. There were
a group of people that used to get together to play jazz
records. They'd come around to various houses. Then Clyde
Clarke had a radio program. In fact, I still see Clyde every
time I go to Toronto. He has a colossal collection. He's
never thrown away anything. His wife died, and his children
are grown, so he has the whole house to himself --full of 78s,
LPs, 45 rpms, everything. Anyway, he had this radio program,
and I think it was through that that I may have met some of the
other people. They put on some of these record sessions in
public. I remember carrying my amplifier and stuff down to a
hall for some of them.

Riess: So this doesn't have anything particularly to do with the
university?

Schawlow: None at all. I never took a music course at the university.
Riess: No, but I mean that music wasn't centered at the university.

Schawlow: No, I don't think jazz would have been considered something

appropriate for the university. Although in this little Delta
Jazz Band that I was involved with, we had a banjo player who
was by far the best the musician in the band. He was an

Riess:
Schawlow:

assistant professor of English at that time, named Priestley,
F.E.L. Priestley. And his wife called him "Felp." [laughter]

So what was it? The Delta--?

Delta Jazz Band. 1 They were a pretty rough group. We tried to
play New Orleans style, New Orleans revival. By that time
records had appeared of some of the old New Orleans musicians
who had never recorded before. Oh, it was wonderful stuff. We
really enjoyed it. A number of us wanted to play like that.
It had a beautiful swing. Always had two clarinets when I
played with them, and I was the second one. We made a few
recordings, but I lost them. Not commercial recording, just
acetates, you know.

We actually made a recording earlier when we were called
the Southern Stompers. Slightly different. We admired--by
that time the books Jazzman and Jazz Record Book 2 had come out,
and they greatly influenced my interest. I tried to get a lot
of the records that were mentioned in them, and build up my
collection.

The way the Delta Jazz Band came to an end was thatwell,
we weren't really very active, but when I got my Ph.D. I had a
post-doctoral fellowship to go and work with Charlie Townes at
Columbia. My sister was very proud, and she knew one of the
university's publicity people and told him they ought to get
that in the papers. He said, "Well, I don't know." But he
called me up, and I told him--I could see he wasn't very
interested in it--I told him that, "Well, fellowships are
breaking up our Delta Jazz Band, because our banjo player is
going to England on a Nuf field Fellowship and I'm going to
Columbia." Boy, they really ate that up! It appeared in the
national news of the Canadian Broadcasting Company.

They liked that twist.

Yes. I had a record of the Delta Jazz Band. I can't find it.
Vanished. But I know somebody in Toronto, I think, who may
have a copy of it. I'll have to pry it out of him.

'For more on Toronto jazz see Toronto Jazz, A Survey of Live
Appearances and Radio Broadcasts of Dixieland Jazz Experienced in Toronto
During the Period 1948-1950, by Jack Litchfield, Harmony Printing Co.,
Ontario.

2 Jazz Record Book, by Charles Edward Smith, with Frederick Ramsey,
jr., Charles Payne Rogers and William Russell. New York, Smith & Durrell,
1942.

Riess:

Schawlow:

When tapes became popular, did you turn all of your records
into tapes?

No, not until much later. Actually I built a tape recorder
with the help of a machinist from the universityvery early,
about 1948 or so. It was a reel-to-reel recorder, of course.
In fact, it didn't even have a capstan drive; one reel pulled
the tape off the other one. Actually, I've still got some of
those tapes. If I ever get time, I'm going to sort through
them and see if there's anything worth listening to on them.

No, I kept buying records. Tapes--! don't like reel-to-
reel. In fact, I don't even like tapes at all because you
can't find anything on them. I much prefer discs from that
point of view. Except they're [tapes] good for getting a lot
of stuff. After the LP came out I started buying LPs in 1950.
Well, 78 rpm records seemed such a nuisance after a while.
They took up a lot of space, and to keep changing them was
really a nuisance. So eventually, I think somewhere around
1980, I worked for several years and taped all the 78s. Then
gave them to Stanford University's Archive of Recorded Sound.

[Schawlow plays a minute of Bob Crosby band, featuring Irving Fazola]

Seeing the Possibilities in a Career in Physics
[Interview 2: August 21, 1996] ##

Riess: I want to ask you about the facilities of the University of
Toronto. Would you use the library at Victoria College?

Schawlow: No, I wouldn't use the library at Victoria College. It was
quite a long way away from the physics department where we
spent most of our time. The physics department had its own
library. And for general things the university library was not
far away from the physics department. I don't think I ever
used the Victoria College library.

They're having a hard time with the colleges, Victoria and
the others. They're losing their function. They were modeled
on the English colleges where there's a lot of tutoring going
on. I don't think they ever did that, but they did require you
to take one cultural course at least, and they taught most of
the cultural courses in the college. I mean, they had an
English department, and Greek and Roman history, and I guess
other history, too. But gradually, the university has taken
over those functions. Now they don't quite know what their

function really is, except that they do provide a dormitory for
those who live there and they provide some social life which I
didn't participate in at all because I'd just go home on the
streetcar at night.

I think we had a pretty good library system. Anything I
needed, we had.

Riess: And that was where you would have found the latest review and
journal articles that were important to you?

Schawlow: That would be in the physics library. As an undergraduate, I
didn't really need to use that very much, but 1 did as a
graduate student .

I was also a member of the American Physical Society. I
joined after I came back from World War II, but maybe even
before that. We'd get the Physical Review, which had most of
the important papers in physics, and the Physics Abstracts,
which were then only about forty pages thick. I would read
through the whole thing, at least skim through everything in
all branches of physics. But now, a year's Physics Abstracts
are, oh, about three feet long, something like that, and they
don't give them away. If you're going to subscribe, I think
it's something like a thousand dollars or more, so I gave up on
it. But when I was a graduate student, I would read it all the
time. Then if I needed to look up any of the articles, the
library had a pretty good collection.

Riess: You had said last time that you took a couple of the cultural
classes. What did you take?

Schawlow: In the first two years I think I took French. This was French
literature- -it wasn't very profound and I'd had French in high
school. It wasn't too difficult either. I also had to take
first year scientific German, which again wasn't difficult
because I'd had German in high school. In the third and fourth
years I took Greek and Roman history. I think it was Greek one
year and Roman the next. Very interesting, but I didn't really
put a lot into those classes. I chose courses that did not
require writing essays, because I was so tired of writing
meaningless essays in high school when I had nothing to say.
In that way, I completed a four year course at a good
university without writing a single essay, although I did write
lab reports.

Riess: I wonder if you felt cheated of a certain kind of education in
the humanities that could have been provided if they had
systematically looked at physicists or scientists as people who
were likely to be otherwise distracted.

Schawlow: No, I guess I have an unorthodox view that I think if a person
is good at something, you ought to let him do it and do it
well. I think it would have been a shame to make Bach or Mozart
study calculus. [laughs] Well, I am no Bach or Mozart, but I
think one can pick up an awful lot of cultural stuff rather
more easily than you can pick up science. You can read the
reviews in the New York Times and other journals, magazines.
I'm not widely read in the serious literature, and I don't read
modern novels, but I think you can pick that stuff up more
easily than you can science. Science was a full-time
occupation, really. I found it quite hard.

Riess: How about reading in philosophy?

Schawlow: I have never done any, and what I've read hasn't made any sense
to me, so I'm probably wrong on that. I'm really pretty
ignorant of philosophy.

Riess: At that age, or even an earlier age, what did you think about

your possibilities? What sense did you have of knowing who you
were? Do you feel that you knew, or were you floundering?

Schawlow: Well, no, I think at each stage I wanted to take advantage of

the opportunities that I had. As I think I said before, when I
started out I thought, "I can probably end up teaching high
school or maybe do something involved with radio." I didn't
know whether I could go on to do graduate research for a Ph.D.
or something like that, it really was something that I thought
was beyond me. But I didn't really worry about it there was
plenty to do.

And then, of course, when I did well at the undergraduate
work I thought maybe I could do graduate work all right, and I
wanted to see how far I could go. I didn't know how I could do
at research, not having done it. I thought it would be nice to
do some basic science, basic physics--but I didn't know whether
I could until I tried it.

Riess: I think that scientists are blessed in that they often know
that that's what they want to be doing, come hell or high
water.

Schawlow: I knew what I'd like to do, but I had seen the realities of the
Depression. I was prepared to do whatever I had to do--but I
knew what I wanted to do.

Riess: To do whatever you had to do--in order that you be able to work
in science? Was it like that?

Schawlow: I guess it developed that way. Initially, it was just I would
do whatever I would have to do to make a living. Because as I
say, in the thirties during the Depression that's just what
people had to do. But yes, I think by the time I was mid-way
through graduate study I felt I wanted to go someplace where
there was really front-line science going on and hope that I
could learn enough to perhaps participate in that.

There was a meeting of the Canadian Association of
Physicists in Ottawa. This organization was formed about fifty
years ago, wasn't it? No, 1945--I gave a talk at the fiftieth
anniversary meeting. It was founded because a lot of
physicists, people trained in physics, had done essentially
engineering work during the war, and they were afraid that they
would have to become registered professional engineers to
continue in that sort of thing. So they formed this Canadian
Association of Physicists to look after the professional
concerns. Well, I joined the thing right away. I never was
much interested in that, but I went to a couple of meetings and
they had some physics talks as well as some talks about their
worries about professional concerns.

The meeting in Ottawa had a lot of dull talks about, as I
say, whether they were going to have to register or whatnot,
but I.I. Rabi from Columbia, who already had a Nobel Prize,
came there and talked about the work that had been done
recently in their department by Willis Lamb and Polykarp Kusch,
who had unearthed new information about the nature of atoms and
electrons in fact, a find for which they got a Nobel Prize
shortly after.

I thought Columbia was really the most exciting place in
the world, and I really wanted to go there. I applied, after I
got my Ph.D., to several universities, and I think I could have
had assistant professorships at several places because there
weren't many fresh graduates at that time in "49, but I did get
this fellowship to go to Columbia to work with Charlie Townes.

I didn't know about Charlie, and I wasn't much interested
in organic chemistrythis was supposed to be for applications
of microwaves to organic chemistry- -but I was interested in
microwaves and had been for a long time, even worked on them a
little during the war. And I was interested in them even
before that. So, anyway, it turned out to be a very good
thing .

Riess: Yes. I guess the moral of the story was that that

organization, the Canadian Association of Physicists, was
perhaps a kind of watershed. It's horrible to think that if

they hadn't formed that organization and Rabi hadn't come to
town

Schawlow: I don't know, I think I would have known. I'm not sure. I
think I would have because I did follow the literature quite
closely then on what was going on. But it was one of the
things that triggered it.

Let me say one more thing about it. I gave this talk at
the fiftieth anniversary and I explained about how it had been
started--! didn't really go too seriously into it. But they
printed my talk and they sent me a copy of their journal, and I
see they're still worrying about the same problem of the
professional status of physicists, which apparently has never
come up in the United States at all.

Riess: One of the things that you mentioned was that research money
stopped during the war. Universities had to make a decision
about research money or not.

Schawlow: That was before the war, some time during the Depression that

they had given up their research money. I doubt if it was very
much, but they had an annual research grant from the
university. Sometime in the Depression they were asked to give
it up for a year and Professor Burton--Eli Franklin Burton, who
was the head of the department at that timegave up the
research grant for the year and the university didn't give it
back. I know he must have been able to raise money somewhere
because he had students build the first electron microscope in
North America. That was a big advance and must have taken some
money .

Thoughts on Emigre Physicists, and Family Support

Riess: A bit more on your early years. I wonder whether you had
heroes in science. What about Einstein? Who were your
mentors?

Schawlow: Of course, everybody revered Einsteinextremely brilliant.

It's hard for me to remember. Now I would think probably the
person I would most admire was Faraday, from a hundred years
earlier almost, who did such simple experiments and discovered
entirely new phenomena. But I did read a lot about physics and
physicists and I did admire the ones who had done some things.
The theoretical stuff of Einstein's- -well, I don't think I had
any illusions about being a deep theoretical physicist.

43
Riess: Did you father or mother understand your interests?

Schawlow: They were supportive. I never questioned them about how much
they understood. I think they understood in a general way.

Riess: But if you were coming home, sitting down at the dinner table,
during the high school and certainly all those college years,
did you tell them about what you were doing all day?

Schawlow: Gosh, I don't know. I don't really remember. I don't think we
would talk about specific physics problems. With my mother I
talked about my general difficulties. But I can't remember at
all.

Riess: Do you think the family was very focused on your success?

Schawlow: No, they were supportive but I don't think they were focused.
Certainly they strained hard financially to get me and my
sister through college. We were both there at the same time,
and we both had had scholarships, but even so that was quite a
burden. My father acquired some debts, I don't know how much
they were. He never would discuss that with me.

Fortunately, after the war he'd bought a house. They [the
owners] wanted to sell us the house we were living in for
$3,000, but we didn't think it was worth it, and my father
bought another one for $6,000, I thinksold it a few years
later for $15,000. Got another smaller one, and I think later
sold that for $23,000. That was the only thing that got him
out of debt.

Riess: That's interesting. He put some work in on the house, or is
this just general inflation?

Schawlow: No, just the general inflation. The inflation of houses was
very fast in fact, has been almost all the time since then.

Riess: Was there a population of emigre physicists who came to Canada
like there was in the states in the late twenties and thirties?

Schawlow: There had been, but there weren't a lot around. There was a
German physicist named Kohl who was a specialist in the
construction of vacuum tubes. He gave a series of lectures on
electronics. 1 listened to him twice, but it was unfortunately
the same both times. Actually, he came to the Stanford area
later and worked for one of the companies--! think also gave
some lectures. But he wasn't right in the physics department.

Let's see--oh yes, the most famous refugee was Infeld,
Leopold Infeld, who had worked with Einstein on cosmology. He

was Polish and he was professor of applied mathematics. I
never worked with him. I heard some of his lectures, but 1
didn't have a course from him either.

Inf eld- -it's a sad story. He was Jewish and the Jews had
been persecuted considerably even before the war in Poland, as
in Russia too. But after the war he thought that the new
government there, which was Communist, would improve things,
and he wanted to help rebuild science in Poland. Well, the
prime minister of Ontario was a Conservative named George Drew
who kind of jumped on him for helping these Communists, and
essentially made things unpleasant enough that Infeld left and
went back to Poland.

Riess: My question is partly why there weren't more, and whether the
ones who came gave Canadian science a kind of jump start?

Schawlow: I don't think they did. There weren't enough of them.
Riess: They went to Chicago and they went to Caltech.

Schawlow: Yes, Gerhard Herzberg went to Saskatchewan and then to Chicago,
and finally after the war they brought him to the National
Research Council. But he was never in Toronto except perhaps
as a visitor. He was a preeminent molecular spectroscopist and
got a Nobel Prize for that later.

I think there was some anti-Semitism in the university. I
never heard it talked about, but I don't think there were any
Jewish professors in the university at that time. There are
now, of course, but--. And that may have been another reason
why they were not so keen to take in European refugees . It ' s a
pity, because there were certainly some great ones available
for almost nothing.

Riess: You said your father chose to tell you that you were partly

Jewish when you were seventeen. When you were seventeen it was
1938, two years before the onset of World War II. When you
think about it now, why do you think that he chose to tell you
then?

Schawlow: It's hard to tell. He had a sister who was still living in
Latvia, and he was trying to see whether we could afford the
money to bring her to the United States because he felt the war
was coming. I think he decided in the end that we could not
afford it, so I don't know what happened to her. But I think
it was connected with that. I don't know, I guess he thought
it was time I should know. I didn't react to it in any
particular way, I think; it was a factnothing I could do
about it one way or the other.

A5
Riess: In science, particularly, it's a really fine heritage.

Schawlow: Well, I think also there was a Jewish tradition of supporting

the son who was a scholarusually a scholar of Hebrew and that
sort of thing, the Talmud. I think they treated me that way.
1 spent a lot of time up in my own bedroom, studying or working
on radios or something like that. They really were quite good
to me, and I think they were generally supportive. There was
never any question that I shouldn't go on as far as I could as
a scholar.

I wouldn't say it never entered my mind that I could be a
scientist, but I remember my father saying more than once that
I should study German because if I wanted to do serious
science, I'd have to study in Germany sometime. Well, the
world didn't go that way. In fact, we had young Germans coming
to work with us. Later, I gave some lectures in Germany. So
the thought that I might be a scientist was not entirely out of
mind [pauses] but, I think I tend to concentrate on more short-
term things.

Graduate School Years The Master's Degree

Riess: What do you mean you think you tend to concentrate on more
short-term things?

Schawlow: You know, I was wondering, sort of thinking back, "Why didn't I
dig deeper into the textbooks and get more advanced books on
science and so on?" Well, I didn't do that. I read all around
it. I mean, I was very interested in things on radio in a
qualitative sort of way, not really quantitative. And I read
all the papers I could find on microwaves at the time when they
were classified during the war. I found that the Germans had
published more than the Americans or British had. I took those
out of the library.

Your mentioning libraries reminds me that our university
library had a complete set of the philosophical magazine
published by the Royal Society in England, and the first
article in the first issue was "Mr. Cartwright's Patent Steam
Engine Which Can Also Be Used as a Still." [laughter] I
remember going into the library and looking around and looking
through those old journals. They had a pretty good collection
of old journals there. Of course, it wasn't as difficult as it
is now because there are so many thousands of journals. Prices
are so exorbitant. But they had a good collection of things
that were published even before the university was founded.

Riess: That idea, that maybe you were thinking short-term, or
whatever, I guess it's a big mantle that gets laid upon
scientists.

Schawlow: I don't know anything, I think sometimes. But you learn a few
things. As I'll probably say later on at the appropriate time,
or maybe several times, I learned that to discover something
new you never have to know everything about a subject. You
just have to recognize one thing that isn't known, to look for
the gaps.

I think that really came to me, though not so explicitly,
when I was midway through our graduate studies. Professor
Crawford had told me to build this atomic beam light source,
and we built it- -two other students helping, one had built the
spectrograph. Then we had to decide what to do with it, and I
did most of that work. I looked through the library to find
out what atoms had not been studied with the kind of resolution
you could get with an atomic beam light source. Finally, we
did some work on silver, zinc, and magnesium.

Riess: I was going to ask you exactly that. How had you kept up with
the literature to decide what to work on with your atomic beam
light source?

Schawlow: Well, I fortunately knew enough German that I could read some
of the old German papers the best work had been done in
Germany before the war, and in England, too. You know, one
paper leads to another. You get a reference, and it leads you
to some earlier paper, and you can track things. The
scientific literature is highly cross-linked becauseat least
they have in the past felt responsibility to refer to all the
relevant papers. So I did spend a good bit of time in the
library at that point.

Riess: [reading] 1 "In the United States [in 1927], many senior

physicists watched the development of the quantum mechanical
revolution with a sense of frustration. For some, the
mathematics of the new formalism was simply too difficult. And
all who were concerned with the philosophical implications of
the new physicsparticularly the middle-aged men whose
thinking had been formed in a more certain world were bothered
by the seeming subjectivism of Heisenberg's approach." You
went to a university where you probably were taught by a lot of
"middle-aged men whose thinking had been..."

'From The Physicists, The History of a Scientific Community in Modern
America, by Daniel J. Kevles, Harvard, 1987, p. 168.

Schawlow: Yes, I think so. Almost none of our professors actually used
quantum mechanics. I didn't take the formal course in quantum
mechanics, but I had some introduction in atomic theory. It
was really very unfortunate that I never did because there were
good graduate level courses. But by that time I was working in
the light lab as awhat they called a demonstrator, here we
call it a teaching assistant. And I couldn't get time off to
take that course, so I never had a real course in quantum
mechanics.

But I had the feeling there that people there really hadn't
digested quantum mechanics for the most part. Crawford had and
so had Welsh, I thinkbut they also were used to thinking in
semi-classical ways, which could do a lot of the stuff.

Riess: At the beginning of wartime, math and physics at Toronto added
a specialization in radio science and technology. Was that in
fact radar?

Schawlow: Well, it was aimed for radar- -submarine detection, too, but I
think mainly for radar. But I didn't go into that specialty.
I remember asking the head of the department. He said, "Oh no,
you know a lot about radio already "--which was true.

Riess: So, onto wartime. That was your first teaching experience?

Schawlow: No, I really didn't do much lecturing during the war. I think
I gave one course, but mostly I was just a laboratory assistant
or led discussion sections--one of the professors would teach a
large class, and then the students would meet in smaller groups
with some of us and we could answer questions or work out
specific problems for them. And I think we helped them in the
laboratory too.

Riess: This is the army and navy guys?

Schawlow: The army people were given our standard undergraduate physics
course basically, which is a rather formalized, standard sort
of thing. There were standard textbooks and standard topics
that were covered, and it was pretty much the stuff we'd had
earlier as undergraduates a few years earlier.

The navy [chuckles] --well, they tended to be submarine
detection technicians, and they were told that you had to have
six months at sea and you don't get seasick, that's all that
was required. So some of them came in not knowing much, and we
had to do as much as we could with them.

Riess:

Schawlow:

Riess:
Schawlow:

Riess:

Schawlow:

You're well very known for your demonstrations and I wondered
whether you developed some of those techniques back then?

No. But we did have at least one professor who gave very
spectacular demonstrations in our first year physics class,
mechanics. We had demonstrations in all the first couple of
years physics classes, but Satterly, John Satterly, was one who
really put on some pretty fancy demonstrations, especially in
his liquid air lecture, in which he was following a tradition
of the time when he was a student when people would go around
putting on putting on liquid air lectures and demonstrations in
the music halls or someplace like that, just as entertainers.

Like a magic show?

Yes, right. Because people were just not familiar at all with
the strange properties. He did a lot of experiments, but one I
remember: he'd put a loaf of bread in a great big pan about six
feet across and then pour liquid oxygen on it, set fire to it,
and the flames would reach up almost to the ceiling. It was
spectacular.

Another one- -he'd dip a piece of rubber hose into liquid
air and, of course, it got very brittle and you could crack it
up like that. Then he took a couple of goldfish and put them
in liquid air. Then he'd smash up one of them. The other one
he'd put back in the bowl, and in a little while it'd be
swimming around again. I asked him once, years later, how he
could do it. "Well," he said, "you just have to be careful not
to damage their scales." Anyway, those were spectacular sorts
of demonstrations.

It's interesting, they do connect to a tradition of magic.

I don't know the specifics, but I have heard about it, that
there used to be vaudeville people who'd go around doing liquid
air demonstrations and talks. Of course, in those old pre-
television days there were the Chattauqua lectures, and a lot
of others in England. People would want to know about the
latest discoveries of science in a digestible way--at least the
wonders of science.

Is it also the wonders of science and seances?
of the century, weren't people seeking that?

During the turn

Some were. Oliver Lodge was a very fine physicist who became a
spiritualist and spent a lot of effort trying to communicate
with the dead--with no great success.

Riess: Now, when you started to do your work for the MA degree, was
that a time when you might have, if it had been at all
possible, come to the States and begun your education here?

Schawlow: Well, yes, but I didn't know what to do during the war. I
guess when I started on my M. A. --probably '41--the United
States was not yet in the war, but they soon were. Well, I
just didn't have enough initiative to seriously consider going
somewhere else at that point.

Riess: Because you're really caught there on the fellowship issue, as
you say.

Schawlow: Well, at that pointthat was in '45 when that became apparent
--my sister got a fellowship to go to Wisconsin to study
English and she spoke to the physics department chairman and he
assured her that they would gladly give me a fellowship to go
there if I'd like to go. But things weren't going so badly in
Toronto, and I thought--. I guess I tend to be rather
cautious. In fact, I've probably missed a lot of good things
by being too cautious.

Riess: Was there also a pull to stay near the family?

Schawlow: Yes, sure, I was living at home and my mother took good care of
me.

Riess: Well, I meant that you would be needed to take care of them?

Schawlow: Not at that stage, no. They were still healthy at that point.
They would be about fifty-five, I guess.

Riess: Would you describe what you did for your master's?

Schawlow: It was a silly thing. It had to be something applied and we,
another student, Morris Rubinoff , and I were tryingthis was
something we did while we were doing the teaching, you know,
just in odd moments --try ing to develop a battery that would be
activated when it was suddenly put in motion somewhere and
spun. Well, we weren't told what it was for, but it was pretty
apparent that it was for something to go into a shell. I
learned later it was for a proximity fuse. So it had a little
glass ampule and fins around the battery things.

We didn't have any priority, we didn't have a lathe or any
tool equipment. We could occasionally get a little machining
done, but it was pretty bad. Actually, we got to the point
where we fired one of these things off in a shell, sent it to
Camp Borden, which is a training camp, and the ampule didn't
break-- [laughs] whereas we'd dropped it on the floor and it

did. I learned later that the trick was to put a little spring
in the thing, make it so that it wouldn't break on a sudden
impact, and make it weak enough so that it would break on a
longer impactas in firing the shell. But we didn't think of
that.

It didn't really amount to anything, but after a year or
so, they said, "All right, that's enough. You can have the
master's degree." The master's degree was not anything very
important. As Professor Satterly once described it, "It's a
bone thrown to an underpaid demonstrator."

Research Enterprises. Ltd., Wartime Research, the Bomb

Riess: During those years was there an equivalent in Canada of Bell

Labs, or a research laboratory associated with a communications
industry?

Schawlow: Well, there was the Canadian National Research Council, and

there even was a classified research program at the university.
I don't know what they did, and I suspect that it wasn't much.
The National Research Council in Ottawa did some radar
development, but I think the level just wasn't really very
high. And of course, I didn't get invited to join this group
even in the physics department. I don't know whether it was
because they thought I wasn't good enough, or because I was not
a Canadian citizen, or because the professors who were doing
the teaching wanted me. But I knew the people who were running
that, and I doubt if anything very worthwhile came from it.

Riess: The level of wartime research on the East Coast, at MIT--

Schawlow: Yes, if you went to MIT or Chicago or Columbia or Harvard very
good things happened. They did move a lot of people from all
over the country to theseand Los Alamos, too to these
projects. But I suspect there were a lot of universities that
managed to keep going in a small way, and not doing anything
very important.

Riess: Maybe since it was a British country all the research would
have been sent off to England.

Schawlow: Yes, the most important work was. People there still thought
of England as the mother country and looked up to it. The
people at the National Research Council did develop a microwave
radar with a wave-guide antenna, which is what I worked on,
trying to get in final shape for installation in the last year

of the war at Research Enterprises Limited. But I think it
really wasn't a very smart design. It was too sensitive to the
temperature.

Riess: Was Research Enterprises Limited formed because of the war?

Schawlow: Yes, it was strictly a manufacturing company. They were set up
during the war and they made. some optical equipment, including
some teaching lab stuff --spectroscopes. They made rather nice
spectroscopes, of which we had a few at the university. But I
think mainly they made radar equipment . When I did go to work
there, I saw one radar setup, a portable radar that required
eight trucks, [laughter] I think a couple of them were spare
parts or something like that.

Riess: Did Canada get ahead of the United States in radar work?

Schawlow: I don't think so. Britain did.

Riess: I read that the magnetron- -

Schawlow: That was British.

Riess: And was the magnetron given to Canada for Canadian research?

Schawlow: I think it must have been, but I don't think they did anything
more than use it. They never published a set of books like the
MIT Radiation Lab did to report what they had done. I guess I
just never heard.

Riess: Did you feel that you were involved in the war effort?

Schawlow: Yes, but I didn't really think I was making a great

contribution. I did what I was asked and I felt it was
probably helpful for the war, but I didn't think it was going
to make a big difference.

Riess: You were testing components.

Schawlow: Yes, basically. I worked at Research Enterprises during the
summer of 'A3, I guess. And then in '44 I moved there after
they finished courses for the army and navy at the university.
When I was there for the summer we were testing transformers
and capacitors. When I worked there, we were using these
slotted waveguide antennas, trying to adjust them so that they
would work.

Riess:

Slotted waveguide?

Schawlow:

Riess:
Schawlow:

Riess:

Schawlow:

Riess :

Schawlow:

Yes. It's a long piece of rectangular pipe- -oh what was it?
about three inches by an inch and a half or so. And they had
slots in the face that were supposed to be spaced a half a
wavelength apart so that the radiation leaking through them
would all be in phase in a forward direction so they'd get a
good beam. These things were quite big, I think about ten feet
long or so, maybe longer. We would check them in the lab and
then mount them up on the roof on a turntable. Then we had a
receiving station across the valley, a mile or so away, and
we'd measure the pattern to see if they had a good directional
pattern.

These slotswe'd measure them first; the trouble is that
the effective wavelength of the waves in the waveguide depends
rather critically on the dimensions of the waveguide. And they
weren't all that precise and so we'd measure one, measure the
wavelength in the guide, have the slots put in, and then check
it. But since it depended very critically on the dimensions
of the waveguide, that is the width, if the temperature changed
then that would change, and they would not work so well. I
think it worked, but it wasn't really a very good scheme.

That sounds very frustrating.

Yes, well, I don't know, I didn't really try to improve it. I
just said, "Okay, we'll do what we can with what we have here."

Do you think that people, at some level, were in touch with the
MIT Rad Lab?

Oh yes, I think so. And with the British. I think in Ottawa
they wereand maybe some of the people at Research
Enterprises, but I wasn't. I did have a security clearance,
but it was pretty low- level stuff that I saw.

I'm trying to think about whether you would even have time to
stop and think about this thing you were working on, and think
in your mind about how it could be improved, or whether you
were like a factory worker practically.

I think I was more like a factory worker,
creatively about it, I'm sorry to say.

I didn't think very

Well, do you think that that's you or do you think that's just
the kind of nine-to-five nature of the job?

I think it's probably both. I think it's probably the nine-to-
five nature--! wasn't responsible for it any more than doing
what I was asked to do, and I did that as conscientiously as I
could, but I didn't really dig deeper.

Riess: So you were doing that up until the end of the war?
Schawlow: Just about a year, yes.

Looking back, I probably should have studied physics while
I was doing that, because we had to take qualifying exams for
the Ph.D. on the undergraduate work and I felt it necessary to
study for a year before I took those. Instead of taking them in
the fall of '45, I took them the fall of '46. Of course, I
started on the research before that, but nothing would have
stopped me from studying for those exams while I was working.
I wasn't being pushed that hard on the work. I could have
worked on it at night but I didn't.

Riess: Were you still being supported by scholarships there?

Schawlow: No. During the war I was paid, not a princely sum but I was

being paid for the teaching and later for the work at Research
Enterprises. It was something like forty-five dollars a week,
I think, for the teaching. Then when I came back there were no
scholarships available, but I could get this teaching
assistantship, or demonstratorship.

Riess: And then that was the year that you studied for your exams?

Schawlow: Yes, and I think I started planning on the research. I

remember coming over to the university somewhere around the end
of the war and talking with Professor Crawford outside the
building about what I might do, and he suggested atomic beam
light source. That sounded good because you could get some
properties of nuclei, and what I really would have liked to do
at that point was nuclear physics. There wasn't any
accelerator and I couldn't get any closer to nuclear physics at
Toronto than what I did.

Riess: The A-bomb, where were you?

Schawlow: Well, I really didn't follow it. I didn't really understand it
awfully well. I knew that nuclear fission could produce a bomb
with uranium. I think we knew even that uranium-235 was the
important part. Oh, one heard rumors that there was work going
on that. There even was an article in The Saturday Evening
Post at one point, I think, that told something about it. But
I didn't know where it was going on or what was being done.

And I thought that you had to slow the neutrons down by
putting them in water, because the slow neutrons had a larger
cross-section. So I sort of visualized thiswell, they maybe
would get some uranium-235 and dump it into the water, into the
bay or whatever, and that would set it off. Of course, that

wasn't at all the way they did it. They did it with an
implosion. After the war, the Smythe report on atomic energy
for military purposes was published and so then I learned
something about what actually had been done.

Riess: But that's interesting that you could 've even anticipated that.

Schawlow: Well, the existence of nuclear fission was known, and as I say
I think there was this article in The Saturday Evening Post
about the possibility that one could make a superbomb that way.

Riess: Maybe they were saying that the Germans were getting this
superbomb?

Schawlow: Oh yes, they were very concerned about that. That's one reason
people worked so hard, to beat the Germans to that. It would
have been a horrible thing if Hitler had had atomic bombs.

Riess: What do you think about the horrible nature of it anyway?

Schawlow: I think it's pretty awful, and I guess I am sort of glad I
didn't work on it. So far, everything that I've worked on,
even when it's the military, has been rather peacefulfor
radar, detecting incoming planes and missiles. I think it's a
shame that they used the thing on people, but I can understand
a little bit of the military mentality because they had
estimates that so many hundreds of thousands or millions of
soldiers would be killed if they had to invade Japan.

Riess: Has it been an ongoing issue for you?

Schawlow: No, well, I read the Bulletin of the Atomic Scientists, and the
Federation of Atomic Scientists, wait a minute, it was the
Federation of Atomic Scientists, now it's just the Federation
of American Scientists it does very good work [publishing
monographs] on trying to reduce the hazards of nuclear warfare.
I think they were in the forefront of pushing to stop
atmospheric testing which would pollute the atmosphere with a
lot of that radioactive stuff. They're still working very hard
to expose the nature of the dangers and try to get people to
stop it. But I read the thing and I don't do anything about
it.

I have not been a political person or an activist. I can
always see both sides of the question. I think if we hadn't
had atomic bombs the Russians would have been even more
aggressive in Europe than they were. In fact, one of the
Russians told Charlie, "If you hadn't had the bomb, we would
have done some things differently," or something like that.

55
Riess: How about when Star Wars was--?

Schawlow: Oh, that was just nonsense. In fact, I was quoted in Time, out
of context, as saying something to the effect that I didn't
think it would work- -whereas I would not have commented at that
point, because I didn't know what secret work was going on.
But I didn't really think there was any hope, and I was right,
even though I didn't know the details.

Riess: You get called upon for quotes, probably, a lot.

Schawlow: Well, that quote was taken from some interview some months

before. Somehow, they dug it out and posted it in Time. I was
a bit embarrassed about it, but there was nothing I could do
about it.

I'm really rather pacificistic in my leaning. I think war
is stupid, any war is stupid, because to kill people to settle
a question is really not right. But on the other hand, I do
see that some people are going to be very desperatethey want
something and they'll risk anything for it. I was at a meeting
in Canada and met a Canadian physicist who had been involved in
political affairs, and he was talking aboutIndia had just had
their first atomic explosion. I said I couldn't understand why
they would want that because it would just makes them a real
target.

He said, "Listen, have you ever heard of triage?" I said,
"No, I haven't." "Well, this is when you divide the wounded
into three groups in a battle, and you patch up those that you
can get back into action first; then, the ones you can get back
into action later; and the rest you just let die."

He felt that if there was a famine in the world India might
be a victim of triage, and that's why they wanted to have their
bomb. Well, that's his theory. Of course, they also have
considerable enmity with Pakistan and China. It's a shame, the
world will divide itself into groups, no matter whether they're
based on race or anything else, but people will fight. Afraid
I try to avoid that.

Riess: Bomb programs are big science.

Schawlow: Well, they're going to nuclear power. It has to be done. It's
not really big science compared to the huge accelerators that
they want to build nowadays, but it's pretty big. I, of
course, held out great hopes for peaceful uses of nuclear
power. The general line then was that power would be so cheap,
they wouldn't even bother charging for it. They didn't realize

Riess:
Schawlow:

all the difficulties, some of which are just due to unreasoning
terror, I think.

People don't know what's safe and what isn't, and they
don't believe the government or the scientistswith some
reason, government certainly has lied to us. But that means
that they just paralyze. For instance, magnetic resonance
imaging for the brain, and the body, is properly known as
nuclear magnetic resonance imaging. However, they deliberately
dropped the word "nuclear" because people were afraid of
anything nuclear, thinking that had to with atomic bombs.

In fact, risk is something that people are studying now.

But you can't really ever get complete certainty in anything.
It's funny, there are more people killed in automobiles than in
wars, I think, but they tolerate automobiles because usually
they're safe--"It won't happen to me." Of course, that's what
soldiers, I gather, would tell themselves. "It won't be me."

[tape pauses]

Schawlow: I'm not sure what interest this part of the history will have
for people. It wasn't until six or seven years later,
actually, that we started working on the idea of a laser. I
don't think people will be that much interested in what comes
between, which is very different. We'll do it anyway, but I'm
trying to think what Joe Public, Joe Sixpack wants. [laughs]

Graduate School Years --Atomic Beam Light Source

Riess: I'm interested in the trip you made to Purdue after the war.
Was this was the first time that you'd even been out of
Toronto?

Schawlow: Well, I'd been to Pembroke before to visit my aunt and her
family and other relatives there. The first Canadian
Association of Physicists meeting was in Montreal, and somebody
had a car, another student. Several of us drove down there.
The second one was in Ottawa. These were trips of at least two
hundred or two hundred and fifty miles. But I don't remember
having been on a train before that.

The reason I went to Purduewhat happened was that we
started on this atomic beam light source, and we read the
papers of Karl Wilhelm Meissner and his associates who had

built one of the first ones. I guess Minkowski and Bruck also
had built one around the same time.

Riess: Minkowski?

Schawlow: Yes. And Bruck. I don't know whether it's the same Minkowski
who did cosmology relativity theory. Probably not, but I
haven't ever checked that.

Anyway, we had a terrible time with it. I think we had a
reasonable idea of how to go about it, but we didn't know a
lot. There was nobody around there who knew anything about
vacuum techniques. The electron microscope people, the ones
who had built it, had gone, though it was still being used.
But we had an awful lot of trouble with leaks.

fit

Schawlow: We shouldn't really have been using brass, we should have been
using stainless steelalthough I don't know whether the
workshop could have handled that, welded it. At any rate this
thing was pretty big, between two and three feet high, and the
ports, some of them were three inches in diameter. So when you
evacuate, there's a lot of force from the air pressure on it.

Riess: When you evacuate?

Schawlow: Yes, you have to pump out the air.

I should explain what the thing is. The idea is that you
vaporize some substance, some atoms that you want to study.
The atoms will go out in all directions, but you put a baffle
in between that part where the oven isthere's an oven at the
bottoma baffle that will only let those that are within a
small angle go through. So you get a narrow beam. You don't
get very many because you're throwing away most of the atoms,
they go out in all directions, and you only take those which go
through the hole.

And then up above that we would bombard them with electrons
and produce light, the idea being- -this is to get rid of the
Doppler-broadening. That is, all atoms, if they're free,
they're moving around rather quickly, so some are coming toward
you and they emit a slightly higher frequency, shorter
wavelength; others are going away, and since they're
random, it just results in a broadening of the line which wipes
out all the fine details that we want to study.

I've often described this in lectures that it's like sound:
if the source goes toward you [high-pitched voice] it goes up

Riess:
Schawlow:
Riess:
Schawlow:

in pitch; if it goes away [low-pitched voice] it goes down in
pitchtowards you [high-pitched voice], up in pitch; away,
[low-pitched voice] down in pitch. That's the Doppler effect
slightly exaggerated, [laughter]

We were trying to build this thing to cut out the Doppler-
broadening and I think our design seemed reasonable. After our
first year, Fred Kelly came back from the war. He'd been in
meteorology, I think, during the war. He did part of it and I
did part of it, but we were having so much trouble with the
leaks. When we'd get a leakwe didn't have a helium leak
detector which were beginning to appear, but we did have a big
tank, about five feet square, and we'd fill that with water.
We'd take the apparatus apart and put plates over all the
openings and blow air into the thing and look for bubbles. If
you'd find the place you'd have it resoldered and then put it
back together again- -and it'd take about a week for this and
then something else would crack open!

After a year or so of that I was getting pretty desperate,
and I wanted to know if we were on the right track, so I wrote
to Professor Meissner at Purdue and he very kindly invited me
to come and see what he was doing. He treated me very nicely.
I think I didn't tell him that I was a student, but anyway he
treated me nicely and showed me what he was doing. And he
offered me, if I wanted to come there, he could get me a
research assistantship there. But I decided at that point that
we were pretty much on the right track, and so I came back. I
guess it was a little later that I got kind of disgusted and I
insisted that the machine shop take it all apart and solder it
more tightly, more strongly, and after that it worked all
right .

You financed the trip? It wasn't that Crawford sent you?
No, he didn't authorize it or pay for it. I just did it.
And what you were building was an atomic beam light source.

Yes. The thing is that you could observe the fine details of
spectra with suitable equipment, which the third member of our
graduate student group was building, and you could measure the
nuclear spins and the isotope shifts. Now they had measured a
few things, but there were a lot more elements, and that's
where I had to find out what wasn't done. So I had to read all
the old papers and find out what was done and what wasn't done,
and pick out some other atoms that we could vaporize reasonably
and yet which had something interesting to look at.

Riess:

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

You mentioned that it had already been done in Germany,
couldn't get what you needed from Germany?

You

Riess:
Schawlow:

Well, this was after the war, of course, and the papers in
Germany were pre-war stuff in the thirties and so on, so I
doubt that any of them still existed.

Is it also that you don't fully understand what you're doing
unless you've built your equipment?

[looking for papers] It does make a difference, but at least
since then I've always felt, never build anything you don't
have to.

Is that tongue in cheek, or do you really think that too much
time is spent on fabrication?

Well, that saying, never build anything you don't have to,
that's especially true because a huge instrument industry has
grown up since World War II, and instruments have become much
more complicated, and it just takes a lot of time to build
them; if you're going to design and build a lot of the
instruments, then you wouldn't have time to do the experiments.

[showing interviewer] This is a diagram, from Fred Kelly's
thesis, of the atomic beam light source. There was an oven
down here, and then this was a water-cooled tank in the middle,
cooling this tube. So that defines the beamanything that
gets through here is pretty much directional. Now, compared
with the atomic beams that are used in [I. I.] Rabi's lab, this
is a very crude atomic beam. It gave us a collimation of
perhaps one in ten, or something like that, but that would
reduce the Doppler width by a factor of tenthe equivalent of
reducing the temperature by a factor of a hundred. But you
couldn't reduce the temperature of these vapors by that or
they'd condense. So this was a way to get narrow lines.

Is what you're doing optical spectroscopy, at this point?

Yes, that's right. I didn't really pay too much attention to
the optical equipment- -well, we did work on a spectrograph. We
used what's called a Fabry-Perot interferometer. Meissner lent
us one of his so we could copy it, and that was very helpful.

You took the interferometer apart?

We took it apart and had a copy made. The thing that's tricky
about it is, you use two flat quartz plates that fortunately
were left over from the 1920s. You coat them with some kind of
highly reflecting metal, and then you set them up so that

they're exactly parallelthey're very flat and exactly
parallel to each other and this means a very fine adjustment to
a fraction of a wavelength of light. The mount that Meissner
showed us how to make was a way to do that, get them so they
would be precisely parallel and would stay that way.

We had some fun with the coatings on these. [laughs] We
were working in the ultraviolet and there was just nothing on
the ultraviolet. Nothing about the techniques for reflection,
little information about reflection of thin films in the
ultraviolet. I remembered reading- -the German ones in the
thirties, Schuler and so on, said that they used the hochheim
alloy, which was prepared by Dr. Hochheim of I.G. Farben. I
don't know, I never heard of him after the war, but I even
dreamt about it one night, that he said, "It's just aluminum- -
just put it on good and quick."

Riess: "'It's just aluminum- -just put it on good and quick.'"?

Schawlow: Yes. Or was it "good and thick"? I'm not sure. There are
various accounts of this.

[William M.] Gray was older than we were; in fact, he'd
been a demonstrator when I was a freshman, he already had a
master's degree, but he had gone away during the war. He was a
rather timid person. He built an evaporator where you could
have both plates facing the source, which is a tungsten
filament. You'd put some aluminum on it and evaporate it, but
when you'd start evaporating the air pressure would go up in
the thing; you evacuate as best you can, but then the air
pressure would go up because gas is released from it, gas
dissolved in the aluminum. So he did it very slowly and
carefully, taking twenty minutes or so to evaporate a film, and
the films were just terrible. They had very low reflectivity.

Well, we had a visit about that time from A.G. Gaydon of
Imperial College, London. He was a noted spectroscopist . We
were telling him about this problem and he said, "Well, when
Hilgers"--the famous optical company in England--"coats their
mirrors, they just put on a little aluminum and blast it off."
So then we wanted to try it real quick. But Gray was too
cautious, he wanted to keep the pressure down.

However, he was married, with one child, and a second child
was about to be born, so he had to take some time off to take
care of the first child. And while he was doing that Kelly and
I took over the evaporator and blasted things off and got much
better films. We actually published a paper on that. That was
the first paper I ever published. Later on, electron
microscope people studied the structure of the films and saw

that they were different if they were produced fast. Basically
what happens 1 think is that the vapor pressure of the aluminum
goes up much faster than the evolution of gas, so that if you
heat it good and hot, and fast, then the atoms can beat the air
atoms to the substrate. Of course, ideally we should have had
a super vacuum system.

Riess: Did you have any idea at that time how much you were lacking?

Schawlow: Yes, some of it, but we could do something with what we had.
After we finished I did some work on silver, which turned out
to be wrong, but we published it.

The silver was a very fine structure pattern, and we
resolved it, but there were two isotopes and they were very
close together. We tried to identify the lines with the
isotopes because one was more abundant than the other. Well,
so help me, when we started out the published values were
fifty-three to forty-seven percent. And that we could resolve.
But I think that by the time we finished someone had
redetermined that it was forty-nine to fifty-one. Well, we did
it as carefully as we could, and we thought we had the one that
was more intense, but later people got separated isotopes and
found that we were wrong on that particular point. We did put
in some other ideas there, though, that were worthwhile.

Talking about evaporating metals, Kelly had to have a
thesis, so we settled on magnesium and measuring the nuclear
movement of magnesium. Magnesium turned out to be very, very
hard to handle because every chunk of magnesium we'd get, the
outgassing was just terrible, and we couldn't just blast it off
with the atomic beam. We had to have a steady beam. It
required, oh, about four hours exposure, something like that.

There was a professor in metallurgy who had come recently
to there from a government lab--I think it was Chalk River--and
he had worked on a process for refining magnesium, and he had
some chunks of magnesium that had been vacuum-melted. He gave
us a few pieces, and with those we were able to do the
magnesium. But with any commercial magnesium we couldn't do at
all.

One of the other problems that I may have mentioned in the
notes that I wrote was that although this light source's
electron beam gave a current of a whole ampere, it really
wasn't very bright, and that is because we didn't have very
many atoms when you have to filter them out and get only those
going in a certain direction. I guess I didn't quite explain
there that you have to have them in one direction because then
you can observe them perpendicular to the direction of the

Riess :
Schawlow:
Riess:
Schawlow:

Riess:

Schawlow:

beam, neither going toward you nor away from you, so you don't
have the Doppler-broadening. At least, it's much reduced.

We required, at least for the silver, exposures of about
four hours at night--day or night. But if the air pressure
changed, that changed the effective spacing between the plates
and would blur out the pattern. The first solution, obviously,
was to put the plates inside a box with quartz windows. We had
to have quartz because it was working in the ultraviolet and
glass doesn't transmit down there. Well, they couldn't afford
to buy us a couple of quartz plates. They didn't have to be
real good optical quality, but anyway, we couldn't get the
quartz plates.

We called up the weather bureau and found out--. We knew
that we had to hold it within a hundredth of an inch of
atmospheric pressure, a hundredth of an inch of mercury during
exposure. And the only time where that would ever happen is
between midnight and four a.m., because otherwise the daily
variation of atmospheric pressure is much more than that. So
we had to start out, get everything ready, and start the
exposure at midnight. We were recording the data on
photographic plates, and if anything went wrong, well, it was
lost, but we had to stay on to vaporize all the silver or other
metal because otherwise we'd crack the crucible when it would
be solidified. So I'd be coming home at 4:30, 5:00 in the
morning, and there aren't very many streetcars at that time, it
was kind of chilly.

It certainly was annoying not to have those few dollars to
get those quartz windows, but we had to make do with what you
could do.

And Kelly and Gray were in the same straits?

Yes.

When did you have your Hochheim dream?

It was about that time when we were thinking about the silver,
the aluminum-coating of the plate. Now somebody, a friend, I
think it was Pat Hume, another graduate student, had brought in
a cartoon by George Grosz of a German Ph.D. looking very
formal. So we put that up and labeled it Dr. Hochheim--but we
had no idea what he looked like.

It sounds like one of the best things about all this is that
you were working in a team.

That helped. It really helps. Gray pretty much Just worked on
the spectrometer, which was fairly novel, and the Fabry-Perot

interferometer. Kelly worked with me on the atomic beam
source, particularly worked on the electron-gun, but we all
worked on everything a little bit.

Riess: Talking things out with somebody else is useful?

Schawlow: Oh, yes, that's a big help. It really is. We didn't bother
Professor Crawford much with these details, we sort of worked
them out among ourselves. I remember Gray--he was sitting
there one day just fuming, he really wanted to go and see
Professor Crawford and say he couldn't do what Crawford had
asked him to do in the way he asked him. I said, "For Pete's
sake, just do it any way that works. That's all he wants."
And he finally did it that way. He'd been around--he got his
bachelor's degree I think in 1936, something like that. Here
it was '46 or later, and he was just used to taking orders, and
timid about trying something on his own.

Riess: That is an important thing, and I guess you've had a lot of

experience with that with your own students. How you get to an
answerit doesn't make any difference?

Schawlow: No.

Riess: Efficiency is not a hallmark?

Schawlow: Students are very different. I've had one student who was

quite good, but he could not work alone at alland I really
can't work very well alone, either. This one student, he was
there for a year or so, just kind of fussing and fuming, afraid
to do anything for fear of making a mistake. We had a visitor
from France and they [the visitor and the student] did
wonderful things in a few months. I said, "Well, just go on
and do some more of that." Well, nothing happened until we had
another visitor from Germany and they did some other things. I
said, "Okay, you've got enough for a thesis now." Turns out
this fellow has gone to Lawrence Livermore LabJeffrey Paisner
is the name and he's now in charge of the planning for the
giant national ignition facility. [See also Chapter V]

Riess: National ignition facility?

Schawlow: This is for thermonuclear fusion. They're trying to build it
I don't whether it's authorized by Congress yet or not. They
use laser fusion, where they have very high-powered lasers
aimed at a little pellet of heavy hydrogen and heat and
compress it enough that you get fusion of hydrogen atoms to
produce helium. If you do that, you could get a lot of power
out of it ultimately. But at this point they are trying to
show that they can break even, get more out than they're

putting in. They're not designing a reactor yet.
huge project.

That's a

Riess: It's a nice point, that some people really need someone else.
They cannot create an internal dialogue about a project?

Schawlow: Yes, I think I need somebody. I really work much better with
one or two people. At Bell Labs I had a technician who worked
with me. I think I might 've done better if I'd been working
with another physicist, but that wasn't the way we worked at
Bell Labs.

Riess: Before we make that leap, this first publication, did you get
any kind of response to it?

Schawlow: Well, the only thing I remember is that it was just a letter to
the editor of the Journal of the Optical Society, which was
something less than a page in length. One of the assistant
professors at Toronto, David Scott, had taken over the electron
microscope, and he did some electron microscope studies on
films that were produced fast and slow, and showed the
differences in the structure. So that was some response.
Otherwise, I don't know. I guess Hilgers had produced good
films and probably others too, but there was nothing very much
out in the open literature telling you how to do things .

[tape pauses]

Schawlow: I was never really deeply involved in radar, except in that one
year.

Riess: Radar was so new?

Schawlow: Yes, oh yes. It was a great surprise to the Germans. I heard
that the British let it be known that they were feeding carrots
to the night fighter pilots so it would improve their night
vision, whereas actually they were using radar. That was a big
surprise and a great help to the British in the Battle of
Britain, although the Germans by the time were also working on
radar. I don't think they had it in the airplanes at that
point, but I really only know from reading some popular books.
I wasn't deeply involved in it.

Riess: In terms of the development of microwave work, was radar a
necessary step?

Schawlow: Probably- -although we had in the lab at the University of

Toronto a klystron, which was quite new at that time. I think
we had it before the war, or just about the beginning of the

Riess:
Schawlow:

war. This is a low-power microwave tube,
klystrons that are very high-powered.

They now make

This was developed at Stanford by the Varian brothers,
Russell and Sigurd Varian. Sigurd was an airplane pilot and he
wanted to do something to help prevent collisions of airplanes,
so he thought if he had some kind of microwave thing, you could
beam it. I guess he was thinking of collisions with the ground
or mountains and that sort of thing. I don't think he ever
actually did anything on the collision aspect of it, but he and
his brother Russell had a little room in the basement of the
old physics building and built the first klystron.

During the war, they and some others went to the Sperry
Company and developed klystrons for military work. Mostly low-
power, I think. After the war they formed Varian Associates
which developed very high-power things, millions of watts,
which were used, I think, both in broadcast transmitters and
linear accelerators, like the Stanford Linear Accelerator
Center.

Did you know the Varians?

No, I didn't. I never met them. They died before I came to
Stanford, and I'd never been on the West Coast before 1961. I
knew Chodorow and Ginzton, who had worked with them. Ginzton
later became chairman of Varian Associates, but he was a

professor at Stanford when I first came.
Ginzton and Marvin Chodorow.

You got your Ph.D. in 1949.

[pause] That's Ed

There's one more thing I want to say about the Ph.D. Many
years later when I was in China, Shanghai, I was talking to a
group of students and I couldn't resist saying, "Well, I know
you're poor, you don't have all the equipment you'd like, but
we were much poorer when I was a graduate student." [chuckles]
We really were. I mentioned those windows we couldn't get. I
burned out a ten dollar thermocouple vacuum gauge and they
wouldn't buy another one and I had to take it apart and rebuild
itwhich I guess was good experience, but--.

I think the only research money they had was something that
Professor Crawford and Professor Welsh had gotten. By working
overtime teaching during the war they managed to get the
university to put aside some money from their overtime pay for
research, but it was very little. Fortunately, the university
had been pretty good in the twenties and there were some things
left over, like these very fine quartz plates that we used.

Crawford and Welsh, and Women Students

Riess: Okay, now I've read in several places, articles by you, how

much you admired Malcolm Crawford. I want to be sure that he
has been adequately covered. Why and wherefore?

Schawlow: Toronto was so dead in the thirties. In the twenties it had
been an active center under J.C. McLennan, and one heard all
sorts of stories about him. He was a real autocrat and he got
a lot of results, a lot of things done, but he drove away some
of the brighter people. And during the thirties it was very
poor due to the Depression, and the then chairman, E.F. Burton,
tried to find jobs for as many people as he could and he
encouraged them to take themand usually it was the better
people who took them.

But Crawford was a very independent-minded man and he just
kept on doing research. They all had heavy teaching loads, but
he still put in hours late at night and did some very nice work
on basic atomic physics. He told me that he had written the
first paper that showed that nuclei are not like electrons,
that is they're not so-called Dirac particles, the angular
momentum is not simply related to the charge. He did that by
showing that the hyperfine splittings of the two different
isotopes of thallium were not the same. They had the same spin
had different magnetic moments, whereas two electrons will
always have the same magnetic moment. Of course, this is
something that is well known now, but it was at that time an
interesting discovery.

He would talk to us about things. I had some courses from
him. He wasn't a good lecturer, he tended to write everything
down on the board. It's a bad habit that I tended to acquire,
[laughs] But he was clear and he would talk about the basic
physics. And also when you would talk with him he would
discuss and speculate about what he thought might be important
in the future. He was a little man, fairly short, but very
intelligent and extremely hard-working. He unfortunately died
of a heart attack at the age of about fifty-five or something
like that.

Riess: Besides you, did he turn out, a number of--

Schawlow: Oh, a huge number of students, particularly after the war.

Riess: In atomic physics?

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Well, a moderate number in atomic physics. But he was also
working on molecular physics. And after the war there was a
flood of graduate students.

Another professor, Harry Welsh, was a slow developer. He
had a very bad stutter and Burton wouldn't let him lecture. So
he just was running the advanced student laboratory. However,
during the war they were desperate for teachers, so he started
to lecture, and he was a very good lecturer. He was slowed
down by his stutter, but I think if he hadn't had the stutter
he would have been too fast. But he was very clear. I took a
course in molecular spectroscopy from him. He also had many
students, all in molecular spectroscopy.

He later became a big wheel. I think he was head of the
department during the period of rapid expansion in the fifties
and pushed to get a new building, which they did, and build up
the department, really rebuild it. They had several department
heads after Burton, and they were flops. But Welsh took over
and did a great job. He had an awful lot of students. I think
Crawford had about half a dozen before me, before the war, and
so on, but I think he must have had at least as many after the
war in atomic physics, putting a lot of his effort into
molecular stuff too.

I noticed one woman in your class picture,
get?

How far did she

Very sad story, I probably shouldn't say it. She did go to
McGill. I don't know what she did during the war, but after
the war she got a Ph.D. from McGill in microwave spectroscopy.
And she published one paper, which was totally wrong, and then
she got married to another quite distinguished astrophysicist--
his wife had died. They married, and I suppose she had a good
life after that. But it's a pity--this one paper was just so
transparently wrong that I didn't want to refer to it. What
she had done was, she had observed a series of equally-spaced
lines in the microwave spectrum of ethyl alcohol, and these
equally-spaced lines were quite obviously the resonances in the
waveguide.

So this one time was it?

I don't think she did any more after that, yes. I think she
probably did a reasonable experiment, but whoever was
supervising her didn't catch that. I think again probably it
was that McGill--they were starting up after the war and had a
huge number of students, and they didn't have anybody who knew
that field. When I saw her paper I was working with Charlie on
the book and by that time knew something.

68
Riess: It was probably was unusual even to have one woman.

Schawlow: Yes, well, we had about four to start. I think one other
finishedGrace Smith.

Riess: Now are we talking about graduate or undergraduate?

Schawlow: Undergraduate. Graduate years, there weren't any in our group.
There were some women around the physics department who had
Ph.D.s, but they were in very lowly positions or just
demonstrator, which is the sort of teaching assistant. I think
eventually they got to be professors, but it was a long time
coming. I think it was Welsh who pushed that through.

One of them, only one of them, Elizabeth Allin, did
research. Crawford got her active again and she published some
papers. She knew physics well. We had her for a modern
physics course in our senior year of college. But I think she
had sort of given up until Crawford got her back to work on
research. She's still alive, I've had a couple of letters from
her, but she's over ninety now.

Riess: I was wondering whether the war years were an opportunity for
more women?

Schawlow: Well, yes, the only other one was this Elizabeth Cohen, who

took that picture of me. She had a Ph.D., I'm not sure in what
field, and she was employed in teaching during the war. I
guess she must have been around after the war because that
picture was taken in 1949, I'm pretty sure. So she was
probably a lecturer or something like that.

Hindsights

Riess: The picture from your undergraduate yearsit's a strikingly
homogeneous body of people, unlike anything you'd ever see in
California. Were there any Indian students or anyone from the
Continent?

Schawlow: Not undergraduate. Graduate years, we had a student from

India, we had a Catholic priest from Quebec. Both of those
are, well, semi-sad stories. They had to get through in a
certain number of years, I think it was two or three years. So
they did, with a bit of a push, but then they never did
anything more scientifically. The Indian, Manual Thangaraj ,
was from Madras, I think, that is, southern India. He became
president of Madras Christian College, so he must have had a

good teaching career. But I think he didn't do anything in
research after that. A lot of them didn't.

It was not a place that attracted people internationally.
It really wasn't that good. I think it became so later, but--

Riess: So that anyone who was a colonial could have gone to England, I
suppose.

Schawlow: Well, that was considered the great thing. You could get these
1851 Exhibition Fellowships to go study in England, but I
wasn't eligible, not being a British subject. I don't think it
would 've been good, anyway.

Riess: Why? Wasn't Cambridge the best thing?

Schawlow: Cambridge was. Oxford was very good, post-war years. Yes,

they were pretty good places. But the particular things that
were going on therewell, I could get interested in lots of
things .

Riess: What you were doing in your graduate years set you up so
perfectly for what you have continued to do.

Schawlow: Yes. It worked out well. Unlike Charlie Townes, I don't plan
my career very well, I just kind of take advantage of what
opportunities I can see.

Well, yes, it has worked out, in the end it did, but
really, I went through a lot of other things. Microwave
spectroscopy is quite different from optical spectroscopy, but
of course, I'd been interested in microwaves so it wasn't so
hard. But then I worked on superconductivity, and that had
nothing whatever to do with what I had done before. And that
was difficult, I wasn't well prepared for that.

Then, of course, we did fortunately get ideas about lasers
and I was able to get back to optical spectroscopy and lasers.
Now there I've had a very good background for it, having both
radio frequency and optical work, because the radio frequency
ideas carried over into lasers.

Riess: In the Nobel Prize description of you, it says your thesis made
you aware of "the need for a coherent, narrow-band source of

light with which to analyze the structure of atoms..." 1
very tidy.

So it's

The Nobel Prize Winners In Physics, Salem Press, Pasadena 1989,

Schawlow:

Riess:
Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

Yes. That's true. I used to wish I could just reach out and
grab those atoms and make them stand still. [chuckle] But
they wouldn't do that. If they're free, they're bouncing
around .

Is that an image that you really had?

Yes, I had that. Of course, many, many years later we found
ways to slow them down with light, laser cooling, which we'll
come to. Since then other people rather soon learned to trap
them, so they really can hold them practically still and get
them very, very cold so that they have almost no motion. So
they can observe them for a long time without any disturbance
from the motion of the atoms.

That's neat, essential, I suppose,
so physical that you can-

that sense that the atom is

Picture grabbing it, yes. You couldn't grab it, though,
because you'd have to hold it some way, and that would disturb
it. They now have traps, however, which can provide minimal
disturbance to the atoms. That's another one of those--

Well, my three most important papers, really, have been
ones where I put in ideas, theoretical ideas, of a low caliber
as far as mathematics is concerned, which were important: the
one I mentioned on the properties of nuclei where you can take
seriously the nuclear size correction; and the second one was,
of course, the laser paper, the optical maser paper; and then
the laser cooling paper. I did that with Ted Hansch, who was
then at Stanford. He's been here the last week. He's going
home tomorrow. That's H-A-N-S-C-H. His name is Theodor, but
he insists is Tay-o-door--doesn' t like being called Theo or
Theodore, so he calls himself Ted.

That paper was what year?

Nineteen seventy-five. Nothing happened about that for about
six years, I think. Then Steve Chu, who was then at Bell Labs,
sort of rediscovered the idea, and later realized that we had
already published it. But he actually did it, and it's a
rather difficult experiment. We didn't do it at the time,
didn't try, because we were very much concentrating on
hydrogen.

Our interest in hydrogen was because it's the simplest
atom, and therefore the one that you can compare with theory
most closely. Ted was and still is working on hydrogen, but
hydrogen requires deep ultraviolet light and there wasn't and
still isn't a suitable laser for cooling it. You could cool

atoms like sodium that emit and absorb visible lightbut I
guess I shouldn't get into laser cooling any more at this
point.

II COLUMBIA UNIVERSITY

Carbon and Carbide Fellowship

Schawlow: I was just a young student and Canada was a backwater then, I
really felt it. By the time I got toward the Ph.D. I felt
maybe I could do some good science. But all the way I had
never considered becoming a Canadian citizen because I felt if
I was going to do science I would have to go to the United
States. There's some pretty good science in Canada now, but
there wasn't at that time, really. It was really not up to
international standards.

Riess: Okay, I hope you will now continue the story of hearing Rabi
lecture, and talk about Columbia.

Schawlow: Well, I guess there's not much more to say: I went to this

meeting of the Canadian Association of Physicists in Ottawa,
and most of the talks were about the right of physicists to
practice as professional physicists or engineers. I thought
that was pretty dull, but Rabi gave an invited talk in which he
talked about the recent discoveries which led to quantum
electrodynamics, and really was new physics.

I thought that was really quite exciting and that I really
wanted to go to Columbia, so I wrote to him when I was
finishing up and he suggested I apply for the Carbide and
Carbon Chemicals post-doctoral fellowship to work on
applications of microwave spectroscopy to organic chemistry,
with Charles Townes. As I say, I didn't really know his work
at the time. I should have, because we did have a seminar and
some of Charlie Townes' papers had been discussed in there. I
had an atrocious memory for names and didn't make the
connection.

Schawlow: An amusing thing, I don't know how it ever happened, but we had
a neighbor a few doors away who worked for Carbide and Carbon
Chemicals, and he asked me to come over to his place and sort
of interviewed me. Somehow, I was being considered for this
fellowship. I don't think that Carbide and Carbon Chemicals
Corporation really had any say in the thing, but somehow or
other he'd gotten word of it and decided he should interview
me.

Riess: In fact, did you ever have to report back to them?

Schawlow: No. I was the second fellow of this type. The first one,

they'd had him visit their plant in West Virginia, I think, and
he gave a talk, and they found it hard to believe what he was
telling them, though it was true, namely that the peak strength
of the microwave absorption line in a gas doesn't depend on the
concentration, on the pressure, the reason being that it
broadens just as much as itthe total intensity goes up, but
it broadens so that the peak intensity remains the same. And
they found that hard to believe.

The history of that fellowship: it may be that Charlie has
told about it, but Helmut Schulz was a chemical engineer with
Carbide and Carbon Chemicals, and he had a lab accident that
had damaged his eyes, he was almost blind, so they put him in a
position to do some long-range planning sorts of things. He
had the vague idea that one could control chemical reactions by
some kind of radiation that was longer than visible light but
shorter than radio waves, something in the infrared
essentially. But there was no good way of generating those
infrared waves . And so he looked around to see where they
could put some money that might advance that .

At Columbia Charles was working on the interaction of
microwaves with molecules. They also had the radiation lab
there that was still working on millimeter wave magnetrons, so
they were working on molecules and short wavelengths. So they
decided to give the money for a post-doctoral fellowship at
Columbia.

Riess: Did you meet Schultz?

Schawlow: Yes, I did. I met him several times. Nice guy. In fact, he
showed up a few months ago. He's now pretty old, but he was
coming out with his wife, visiting various places. He managed
to drop in and we had a nice chat.

Riess:
Schawlow:

Riess:

So he was the one that brought us together, and in a way
this sort of thingthe fact that we were together--led
eventually to the laser, which does give you a potent source of
infrared. But I don't think controlling chemical reactions has
really been very successful in the infrared. It's partly much
too expensive because photons are expensive to generate, and
most chemistry is done in batches of tons and sells at cents
per pound. Laser photochemistry has been used to separate
uranium isotopes which are, of course, very valuable, and while
that's expensive it is cheaper than other methods of doing it.
I didn't work on that.

When we thought of the idea of a laser, the only
application I had in mind was this thing that Schultz had
suggested, maybe control chemical reactions, because it's
obvious that chemical reactions usually go faster if you heat
them up and here is a very selective way of heating them up.
So at Stanford I had one student working on trying to separate
bromine isotopes, and we were able to get a selective
initiation, but the isotopes were scrambled before the reaction
was completed. What I didn't realize was that if you were
going to do it you had to do it very fast, so that you complete
the process before some competing collisions scramble it all up
again.

After Tiffany did his thesis and leftthat's William
Tif f any other students didn't seem interested in doing what
was clearly chemistry, perhaps not so much physics. Also I
began to worry a bit about the separation of uranium isotopes;
I didn't want to do anything that would speed the day when it
would be easy to make bomb materials. So I decided I just
wouldn't work on isotope separation anymore, other people could
do it. It's okay for labs like Livermore where they have huge
facilities and some secrecy, but it's quite possible that I
might have discovered a way to do it cheaply in a garage or
something like that, and that would be horribleand terrorist
organizations and criminals could get atom bomb materials.

That's about the only time I ever steered clear of any
subject for any ethical reason, but it was partly because
students didn't want to do chemistry, and I guess I didn't
either, to tell the truth.

But they hadn't focused on the ethical issues themselves.

I don't think so, no. But of course, bromine was quite
different from uranium and had no applicability.

So you've described the intent of the fellowship--

Schawlow: In fact I was just another person in Charlie Townes 1 lab, where
he was working mostly on organic materials. But he asked me to
try and see if I could detect the spectrum of a free radical
OH, that is one oxygen atom and one hydrogen atom. It's
interesting that even then his real interest in it was for
astronomy, because he thought there ought to be OH out in
space. He thought if we could detect it, it would be an
interesting probe for the conditions around stars.

I had a hard timeagain, I didn't have the equipment I
needed and that I knew I needed, although they had an awful lot
of microwave equipment. Trouble is that you could find out
pretty quickly that OH can be produced in a gas discharge. I
made a spectrometer with a long tube that we could run current
through to get a discharge, but then the trick was to know when
we were producing any OH. The difficulty was that we could
have done it very well if we'd had a good spectrograph, because
the spectrum was at that time was well knownit's in the
ultraviolet, it was known but we didn't have one.

Columbia had sort of missed the boat in the twenties. It
had been pretty moribund and didn't have a lot of spectroscopic
equipment lying around. And Charlie didn't feel like buying
one. So we tried to use a chemical test that was published
that said that if you have OH, you'll produce hydrogen peroxide
if you let it condense on a cold finger cooled by liquid air or
something like that.

Riess: On a cold finger?

Schawlow: Finger. Yes, you take a jug of liquid air, a canister that

contains liquid air, have a tube going down at the bottom which
sort of looks like a finger. You let the stuff condense on
that, and it's cold enough that it will condense. Well, we got
lots of hydrogen peroxide, but with still no OH spectrum.

I did some other things with people in the lab. I had a
student working with me, Mike Sanders, T.M. Sanders, Jr. He
was quite good, but we didn't get anywhere. We used an
ingenious spectrograph: instead of using electric field
modulation we used a magnetic field, wrapped a coil around the
long tube, and put an alternating current through it so it
would produce alternating magnetic fields. We thought that was
clever, but Walter Gordy at Duke had done the same thing about
the same time and published before us--he used it for oxygen,
which is also magnetic. Whereas normal atoms are not, or
molecules; it's just the occasional one like oxygen, or the
free radicals would be magnetic.

I was there two years, and after I left Sanders and another
student were working there one night when something went wrong
with the discharge conditions and they happened to be sitting
at the right wavelength and saw the absorption lines. So this
hydrogen peroxide test was just a wrong way to tell whether you
had OH or not. Of course, once you have the microwave spectrum
then it's a good test. But I've always regretted that I didn't
have an optical spectrograph to test whether I had OH.

[tape interruption]

Charles Townes and the Microwave Spectroscopy Book

Riess:

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

I thought Columbia was where microwaves spectroscopy was going
on, but they didn't have the equipment you needed?

They had microwave equipment, lots of it, but they didn't have
the optical equipment that I needed to go with it.

And yet, between you and Charlie, you really wrote the book
eventually.

Yes, he asked me to stay on and help him write the book on
microwave spectroscopy. So 1 did stay for a second year. The
fellowship was only good for one year, but he got some money
from the Ernest Kempton Adams Fund, I think, that Columbia had,
to support me for another year. The department had suggested
that I might want to be an assistant professor, but I said I
just couldn't see how I could teach, do research, and write the
book, so I turned that down.

It was a book that was ready to be written?

Well, it's funny. Charlie Townes really wrote the book. He
wasn't the only one working on microwave spectroscopy, but he
was one of the leaders. Walter Gordy at Duke, and M.W.P.
Strandberg at MIT, and D.E. Coles at Westinghouse, those were
the main ones. And there was quite a rivalry between Charlie
Townes and Walter Gordy at Duke. Some book salesman came and
told him that Gordy was going to write a book, and so he
decided that he would write a book too. [laughs] I think
everybody agrees that it was a better book because Gordy was
sometimes a little slapdash.

But anyway, he asked me to help him on it and so I did, I
stayed another year, which was good because that's when I met
my wife, Charlie's younger sister.

Riess:

Schawlow:

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

Let's step back a little bit to have you describe this time.
It's very fabulous for me to imagine you leaving Toronto and
coming to the big city. How did you find a place to live and
how helpful was Charlie? Was Charlie really in your life at
the beginning, or were you just anybody?

He was very nice to me, invited me over to have dinner once or
twice. At one time, they permitted research associates to join
the faculty club. Since they didn't have anywhere else to eat,
I often did eat over there. I got to know some of the
professors that way, both in physics and mathematics.

And where did you live?

When they notified me of this fellowship, they said that I had
to live in the university dormitory. I think that was not
really correct for post-doctoral fellowships, but not knowing
any better I took a room at a John Jay Hall, which I found
rather annoying, but I didn't know any better or what else to
do. I was there for about a year and a half. The thing I
didn't like was the walls were rather thin, so I couldn't play
my records very loud, or even what I consider a moderate
volume, or I'd get complaints.

Also, in New York City and in John Jay Hall they had direct
current. It was a legacy of Edison, who didn't believe in
alternating current. It meant that any kind of radio equipment
wouldn't work unless you got a converter, which I did. I bought
a converter, a kind of a vibrator that converted DC into AC,
but it really wasn't very satisfactory.

You came down from Toronto by train?
Yes, I did.

You packed up a wardrobe and your records,
pack?

What else did you

Did I take records with me? I guess I took some records, and
of course I bought more in New York. I probably brought the
record player, too. Some books.

Were there any formalities of reestablishing your citizenship?

Yes. There was a little bit. I went to the U.S. consulate in
Toronto and presented my birth certificate and said, "Is it
okay? Can I go back?" And I said, "No, I'd never voted in an
election in Canada." They said, "I guess that's all right."
Actually I think I could have crossed the border without
bothering with any of that stuff.

While I was there I registered to vote in New York, and it
was quite amusing, I was told that if you had a high school
diploma you didn't have to pass the literacy test, but a
college diploma only proved that you could read Latin. So I
had to take a literacy test which of course was not difficult.

Riess: Did you go back to Toronto for your holidays or had you really
made a break?

Schawlow: I went back for vacations, some. I did go back several times a
year, and I started to go by plane. The first Christmas
season, I think, that I was there, I went back by plane. And
then the weather was so bad I had to come back by train,
because the plane wasn't flying.

I felt very lonely at first. Although I'd never been a
great lover of gardens or trees and things, I really missed the
greenery. In New York, it was all concrete practically. But I
got to meet people. I joined the Riverside Church and they had
a young people's club that I went to, so I got to know a few
people there. I got to know some of the graduate students at
Columbia pretty well, too.

Riess: And did you get right onto the jazz scene?

Schawlow: I went out there occasionally, yes. I'd visited New York a
couple of times when I was a graduate student. I knew where
the places where, and I would go out occasionally. I couldn't
go very often because it meant staying out very late at night.
They used to close at three a.m. in those days. You'd come
home on the subway at three o'clock and see people like milkmen
going about their business. Nobody would bother you at all. It
was really a nice place.

There were some stores that specialized in jazz records.
It was interesting--! 'd found this the first time I'd visited
there, in '47, that these stores, unlike the ones in Toronto,
knew exactly what every record was worth- -usually priced a
little bit more than what I would pay. The ones I would pay
more for, they raised the price. They knew exactly what they
were all worth.

Riess: You were filling in your collection?

Schawlow: Yes. And expanding- -building a jazz record library.

Riess: Has that been a lot of what being interested in jazz has been
for you, is to create a complete archive?

Schawlow: Yes, within certain ranges. I mean, obviously I can't get

everything that's been done, but for the major artists that I
really liked and admired, I try and get everything I can. I'm
really missing it now: I had complete sets of Tommy Dorsey,
Artie Shaw, and Bennie Goodman that were issued on Victor Blue
Bird label a decade or so ago. I put most of those on mini-
discs and I cannot find those mini-discs now. I'm feeling very
frustrated. They're out of print.

Riess: You'll find them.

Schawlow: Maybe. Or they'll reissue them.

Riess: The Riverside Church, you had your music life, you had some
friends, but the question of whether to stay on the second
year: if you hadn't stayed on the second year, what was going
to come up next for you?

Schawlow: Actually, the University of Toronto contacted me and another

fellow, this Pat Hume that I mentioned before, who had gone to
Rutgers about the same time I went to Columbia, and they asked
us if we'd be interested in an assistant professorship. I
asked if I could postpone it a year because I'd already
promised Charlie that I would stay and help with the book.
Well, that didn't work out, so he [Hume] took the job. I
probably might have gone back to Toronto if there hadn't been
anything else in sight.

Riess: Did you go out to Brookhaven when you were in New York?

Schawlow: No. I didn't. Charlie was there during the summer, just

before I went there. In fact, he was still there over Labor
Day weekend. He invited me and my predecessor Carbon and
Carbide Chemicals fellow to go out there. I got a most
horrible sunburn.

Riess: I've a note that Charlie was extraordinarily effective in

getting the best from students and colleagues. How would you
describe how he worked with you, for instance?

Schawlow: I don't know. He would make suggestions, but he didn't

supervise me very closely, not on a day-to-day basis. He had
weekly meetings with his graduate students and they would
present some aspects of their research to be discussed there,
and I think that helped to stimulate. He had a large group so
they sort of supported each other in some ways; they could
discuss things with each other.

For me, well he suggested various things. After I'd been
there for little more than a year, and I was still stuck on

this OH experiment, he had me help some other students on other
projects so I'd get some publication before I'd have to leave.
I did that. I wasn't terribly interested in it, but I did what
I had to do there. I really still wanted to struggle with the
OH, because that was the first free radical that was found with
microwave spectra.

Riess: Working on the book sounds like it could have derailed you.

Schawlow: Yes, it did some. The trouble was I was not an expert on
microwave spectroscopy at all. I really wasn't. I'd been
there only a little over a year when we started on it, so I
sort of drafted several chapters that seemed like they were not
too specialized. I did chapters on atomic spectra and diatomic
molecules, and then later on pressure broadening and on
millimeter wave techniques. But I had to study these up, each
one, because I really wasn't an expert on microwave
spectroscopy.

Riess: It sounds very uphill.

Schawlow: Yes, it wasand then it kept on and on. We didn't finish it
while I was there. The next three years, I think, I would go
in many Saturdays and work on the book while I was at Bell
Labs. It was a distraction all right, but I felt from the
beginning if we were going to write a book at all, we wanted to
write a classic that would be something that everybody would
respect and turn to, and I think we did. It's been very widely
used and quoted. I think, frankly, Charlie's part was the more
important part, because he knew the stuff and I didn't. But I
did study up some and wrote some of the things .

Meeting and Marrying Aurelia Townes

Riess: Before we finish for today, and since we're being very strictly
chronological, when did you meet Aurelia Townes?

Schawlow: It was in the fall of 1950. I went to Columbia in '49 and I
was there for a year, and I was frankly beginning to look
around a little bit to see if I could meet a nice girl, and I
never took one out more than once. And then she came by my
lab, he brought her around. He'd brought his older sister Mary
before and I didn't pay any attention to her. They kind of
looked in the door and I figured, well, his sister is probably
older than me, I didn't really take a good look.

Riess:
Schawlow:

Riess :
Schawlow:

Riess:
Schawlow:

Riess:

Schawlow:

Then Frances [Mrs. Charles Townes] invited us to dinner and
made sure we got to know each other and we started going out
together. It wasn't very long before I proposed. She took a
little while longer to decide whether she wanted to do it or
not, but by January I think we were engaged.

Was she already living in New York for her music study?

She had been there before to study singing and music in
general. She'd gotten a master's degree in music education
from Teacher's College, and she'd come up this time to take
more studies, mostly with a private teacher, Yves Tinayre. She
did take some courses at Julliard and at the Mannes College of
Music.

She was seriously pursuing this career?

Yes, as a singer. But it's a very hard, competitive field
which she eventually gave up when we got married, pretty much.
Well, she was still going in to New York to work with a pianist
and an accompanist. We moved to New Jersey after a year, in
September of "51, I think it was, when I started work at Bell
Labs. And she was still going on the train to work with her
accompanist and also take lessons from Yves Tinayre.

What were your impressions of the Townes family when you met
them?

They were very nice to me. It was a bit overwhelming to meet
all of them at once, but I guess Charlie had said some good
things about me and they were quite nice to me.

South Carolinawere they terribly southern?

Pretty southern, but they were all very intelligent, and most
of her brothers and sisters had studied in the north somewhere.
I think two of them had studied at Cornell and two at
Swarthmore. They were southern all right, but I wasn't
particularly prejudiced against southerners, which a lot of New
Yorkers were. They were something really just outside our ken
in Toronto. We'd heard about southerners, and we'd heard about
lynchings. I think it was Mike Sanders who said, "When you
meet her father, just ask him, 'Have you seen any good
lynchings lately?'"

I'm very ignorant about the south, but I love the accent. Did
she have an accent?

She did sometimes. She could sort of turn it on and off.
depend on the circumstances.

It'd

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

Did you get married down there?

Yes, we did. That was the first time I met them.

My mother came along and we flew down. At that time the
only plane was a propeller plane, of course, and unfortunately
I think it stopped about five times. They served potato salad
for lunch, and just after the second to last landing it came
up. [chuckle] I remember her father said after I'd been on the
ground a while, "I'm glad to see Art isn't always that color."
[laughs]

It was a small wedding?

Her father had had a heart attack not long before that so they
decided to have the wedding in their garden- -they had a nice
garden. It was a simple wedding. I could show you the video.

Oh! Really?

Well, Charlie had his movie camera and he took some pictures.
I got some copies made on video lately. They didn't do a good
job. Everything looks very blue, but still--we do, yes we have
a little video. Not in very great detail, no sound.

And so from your side, you had your mother and your sister?

No, just my mother came down.

Not your father?

No.

They couldn't afford to?

I don't know why. I think maybe my parents thought he seemed
rather foreign. He still had some kind of a strange accent--
doesn't seem like a Russian accent or anything else, but he had
an accent. I think that was it, but I don't know.

You mean that was the way he felt about himself?

I think probably. We just sort of didn't discuss it.

And by that time my sister was married and had at least one
little child, so it would have been hard for her to come.

She was living up there?
Yes, in Toronto.

Theoretical Work, and Publishing on Hyperfine Structure
[Interview 3: September 4, 1996] it

Schawlow: I've never been a real theorist, but strangely enough I think
several of my best papers have been theoretical. It's a low-
grade sort of theory. I don't do a mathematical calculation, I
sort of look at the subject and present something differently
with a minimum of mathematics .

The thing I wanted to mention particularly now- -I was
working on hyperfine structure of atomic spectra, and I was
interested in what we could find out about atomic nuclei. So I
read papers; you could read about all there was to know about
the theory of nuclei in some pre-war papers. I think three of
them were in Reviews of Modern Physics, by Hans Bethe, and each
one was fairly long, but that's certainly far less than is
known now. But even a simple-minded person like myself could
get the general picture.

So we were measuring hyperfine structures and I looked up
the theorywell, there was a formula from Goudsmit, improved
by Fermi and Segre, which let you calculate the nuclear
magnetic moment from the hyperfine spinnings. Now magnetic
moments were beginning to be measured at that time using
nuclear resonance, and so I thought it would be interesting to
compare them. And I found that one had to take into account
for heavy atoms the finite size of the nucleus, because the
electron wasn't just being pulled in all the way, it was being
pulled in until it reached the surface of the nucleus.

There were papers by Breit and Rosenthal in 1932 about
hyperfine structure. And then a friend who was a student in
applied mathematics, which is what they called theoretical
physics in Toronto, told me about an obscure Norwegian paper
which applied a method called perturbation of the boundary
conditions. You couldn't use ordinary perturbation theory
because going into the nucleus the electron experienced a huge
change in the electric field potential, it wasn't just a small
thing. However, you could imagine changing that radius
slightly and perturbing it that way. So I could calculate the
effects of the nuclear size, roughly at any rate, and we
published this in a paper called "Electron-Nuclear Potential
Fields from Hyperfine Structure" [Physical Review, 1949]. And
this got a good bit of attention.

Riess:

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:

We also did some work on isotope shift. But it was rather
lucky for me that I'd been told about this Norwegian paper by
E.K. Broch, because it certainly was not a journal I would ever
look at.

You were looking for different approaches?
process always in doing physics?

That's part of the

Yes, I think so. Try and do something that hasn't been done
before, that's what you have to do for a thesis, and in fact to
publish, too. You have to do things in a different way or do
something different.

In Charles Townes's book, Making Waves, he seems to be making
the point that since you can't know what you're going to get,
you never can be too focused about what you want. 1

Yes, you have to keep your eyes open and take the results of
the experiment seriously, if you do get results. I've said
before, probably not with you, that when you get some new
results I immediately think of what it might mean. Maybe there
are several hypotheses, it could be this, it could be that, and
then you weed them out one by one. And probably most of them
are wrong, but that's the way you make progress.

How you weed them outthis is where you think your way through
it?

Yes, well, ideas have consequences and you might be able to do
it theoretically, that this doesn't fit with something else, or
you might suggest a new experiment that we should do, another
test, a different test, to see whether that's right or not.

Something that I readthe idea that there's a lot of
literature and old experimental work in physics that people

could work on using new knowledge,
almost an historical physicist.

It's as if one could be

Schawlow: That's right. It's sort of like time travelling, almost, like
the Connecticut Yankee in King Arthur's Court. And we did
that. We'd go back to old issues of Physical Review or other
journals, like the Zeitschrift fur Physik in the early
thirties, and you'd see things they did, and how far they got,
and with newer techniques you could do things that they
couldn't do before. I have often thought that if I ever were
short of ideas, I would just go back and look at old magazines

'Charles Townes, Making Waves, American Institute of Physics, 1995,

twenty or thirty years ago, and see things that have been
forgotten and never followed up. And there are lots of them.

I.I. Rabi pointed out in a book- - there ' s a book about him
that's well, semi-autobiographical actually, written by [John]
Rigden, but with extensive interviews with Rabi. He tells
about his Ph.D. thesis which was a very clever way of measuring
magnetic susceptibility. He says this was never referred to by
anybody, never was a single reference in the literature to this
paper.

Riess: That's interesting. That reminds me of the habit practiced by
physicists of making journal entries. So if you're doing your
daily journal- -

Schawlow: Unfortunately, I've been very lazy about that. I'd rather

think than write. In fact, I was at Bell Labs for ten years
and I think I filled a little over one notebook, and most of
the stuff I put in the notebook was wrong. If I actually got
good results, it usually was something I'd just write on a
scrap of paper.

Riess: Are the notebooks considered to be in some way public property?

Schawlow: No. They can be if they're released, but otherwise not. I

guess mine are still at Bell Labs, I have never asked for them.
They gave me one or two pages from it, but that's about all.
They gave me a copy of one or two pages.

The Atmosphere at Columbia. 1949

Riess: At Columbia, when you were there, there were eight future Nobel
Laureates.

Schawlow: It's now eleven.

Riess: Eleven came out of that lab?

Schawlow: Well, they were around the university in one capacity or

another. Counting Townes and myself there was [Polykarp] Kusch
and [Willis] Lamb, and let's see, Rainwater. Val Fitch was an
undergraduate.

Riess: Val Fitch?

Schawlow: Yes. He's at Princeton. I didn't meet him then, but he was
there as an undergraduate student.

[Hideki] Yukawa, who got his Nobel Prize a few months after
I arrived; he got it in October and I arrived in September.
And let's see, there's Aage Bohr, the son of Niels Bohr.

The most recent onesno, the second most recent ones were
Mel Schwartz and Jack Steinberger and Leon Lederman. Lederman
was an assistant professor at the time. Then Martin Perl got
the prize just two years or so ago. He was a graduate student
at the time.

I don't know if I've thought of all eleven or not, but--.
Well, it was really an exciting place. And physics wasn't so
diffuse as it is now. Well, they sort of concentrated. It was
kind of nuclear physics, and atomic physics details were the
frontier. People could still talk to each other and they did.
We would meet in the afternoon for tea and discuss physics
questions.

Riess: That generosity of time and sharing is unusual?

Schawlow: Yes, I think so, the fact that they could share, that they knew
enough of each other's field that they could trade ideas.

And then Rabi had great enthusiasm. He was considered a
tough man to do research for because he really wouldn't bother
about the details of an experiment. Two students were working
on a problem he proposed, and after working for a year or more
they decided that it just could not be done with that sort of
apparatus. When they told him, he said, "Well, I'm sorry," and
they just had to find something else to do. And they did, but
that ' s sort of the way he was .

But he had great enthusiasm. I remember he went to Japan
for a couple of months, a few months after I came there, and
when he came back he came around and poked his head in the door
of my lab and said, "Well, what have you discovered?" Gee,
the thought that I might discover anything somehow really
hadn't hit me. I think maybe "finding out something," but--.
It was inspiring.

Riess: So he really put his imprint on the department.

Schawlow: Yes, and he had hired a lot of people. He hired Charlie. He
heard him speak, I think, at an American Physical Society
meeting and he lured him away from Bell Labs.

Riess: Then he got Charlie working on the microwave spectroscopy?

Schawlow: Well, Charlie was working on microwave spectroscopy at Bell
Labs. He started it. He didn't stay there because although

Riess:

Schawlow:

they were happy to have him work on it they wouldn't give him
any assistants, so he had to pretty much do it by himself with
occasional collaboration from other physicists there. And he
had a lot of ideas and wanted to have a group, so that's why he
came to Columbia, at least as far as I know. He did build up a
group rather rapidly.

I had the same feeling myself when I was forty and started
getting offers. I had a lot of ideas at that time, and I just
couldn't do them all. I didn't even ask because Bell Labs
didn't, at that time, have people working in groups. So when I
came to Stanford I got a lot of graduate students and we could
try a lot of different things.

Back to Rabi's comment, what is the difference between an idea
and a discovery?

Well, I guess I think of a discovery as being something
important. [laughs] Discovering, rather than finding out. I
don't think it [the comment] changed what I did, but it was
sort of inspiring just the same.

Publications and Timing

Riess: One of the things I'm gathering from what you're saying is that
a lot of papers get written before the actual work is done.

Schawlow: Yes. I don't know whether Charlie told this story or not.
II

Schawlow: Charlie didn't publish the idea of the maser before it actually
worked, and the reason was that in the years after the war a
lot of people were rebuilding labs or building new ones, and
they did write a lot papers proposing various experiments.
People joked that we should call Physical Review "Physical
Previews . "

So by 1951 when he got the idea of the maser it was sort of
Just not done to publish a possibility, you should go ahead and
do it. That's the way he did. He wasn't secretive. He didn't
formally publish it, he put it in his progress reports which
were unclassified and were in some libraries.

He might not have gotten the Nobel Prize- -because you have
to publish for thatexcept that he went to Japan and he gave a
talk and Koichi Shimoda wrote it down and published it. So he

got a publication there on the idea of the maser. Because
about that time, Basov and Prokorov in Russia published part of
the idea. They didn't have anything he didn't have. He had
more, actually, but they did publish part of the idea and they
shared the prize in 1964.

Riess: But the witnessed journal entry, doesn't that count?

Schawlow: No, for patent purposes that's fine. For publication credit,

no, it doesn't work. You have to publish, to get a Nobel Prize
at least, and I think for most other physics prizes. You have
to put your name on something, and often it's hard to decide
when you really are confident enough in a result that you will
publish it.

There's a story about the discovery of what was it? The W-
boson? The thing that Rubia got the Nobel Prize for. There
was another group at CERN, that is the European Nuclear
Research Center, that was working on the same project, looking
for this particle, and knew just what they were looking for.
Well, he met the leader of this group in the hall one night and
said, "We must be cautious, be careful not to publish
prematurely, because we could be wrong." And at that time he
had a courier on the way to Amsterdam with a manuscript for
Physical [laughter] That's a little dirtier than one usually
does, but that's the way high energy physics is.

Riess: I'm surprised that there's not more of it.

This is different from the Rabi and the afternoon tea party
kind of physics.

Schawlow: You keep looking for new ideas and new ways to do things.

Riess: If you talk about new ideas, people might say to you, "Well
that just can't be done," and you can't listen to that, can
you?

Schawlow: No, you have to decide for yourself. Of course, there is the
famous example of Rabi trying to talk Charlie Townes out of
working on the maser. I think he argued that it wouldn't work
and he should give it up, but Charlie had done the analysis
himself and he felt confident, and he was right, of course. I
usually haven't worried too much about that.

There was one case where a theoretical physicist talked us
out of doing an experiment, but it wasn't really me, it was a
post-doc working in my lab that was going to try and do
something and this theorist was visiting and persuaded him that

it wasn't going to work, which was wrong,
did it.

And so somebody else

Riess: Do you think too much energy goes into naysaying?

Schawlow: Some people do, I usually avoid those people.

Riess: Some people do a lot of naysaying, you mean?

Schawlow: Yes, I think so.

I tend to try to believe everything, but check it out.
Even crazy things, you know, if they are excitinglike cold
fusion for instance. You look at it at first and see, well,
what does that imply; after a while you decide that couldn't
be, at least not the way they described it. But I do know
people who immediately have a negative attitude. They know
what they know so well that they really can't fit in new ideas,
And they're not very productive.

Seminars and Group Meetings

Riess: Were you the only post-doc when you were there?

Schawlow: No, there were two others. My predecessor as the first Carbon
and Carbide Fellow was Jan Loubser. He was a South African who
had obtained his Ph.D. at Oxford and he was there for a few
overlapping months. Then there was a Norwegian chemist named
Eilif Amble. Those were the only two in Townes' group at that
time.

There were a number of young people around. There was this
young Bohr, who I don't think had a Ph.D. at that time because
the Danish Ph.D., like some other Europeans, really requires a
lot of publications. It's not just one publication, like you
need for an American Ph.D. And he really knew far more than
almost anybody else, and he was a great pleasure to talk with.
We had some interesting discussions.

I remember once there was a seminar and John von Neumann
from the Princeton Institute for Advanced Study came and talked
about the theory of turbulence, which is a very difficult
subject. Bohr seemed to understand it very well; I don't think
anybody else did. He was running the theoretical seminars and
he asked me to talk about what I had done on this theoretical
work on nuclear size measurements from hyperfine structure.
Well, I foolishly agreed.

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

When I got in there, God, there was Rabi, Yukawa I think,
and of course Townes, Willis Lamb, and Norman Kroll--a whole
line of theorists. Well, I knew what I knew, and I didn't know
any more than that. So 1 said something, and if somebody asked
a question I'd pause, and usually the person next to him would
answer it. But afterwards, one of the other graduate students
said, "Boy, you were really shaking!" [chuckle] I was.

Theoretical seminars were built into the program?

For the whole department, actually. They had the colloquium,
which would address everybody, but they would have the topics
in the frontiers of theoretical physics. And they would have
small audiences; maybe thirty people or so would come to those,
whereas a couple hundred might attend the colloquium.

But that wouldn't be a place where people would come and talk
about ideas they were working on?

Yes, they would be.
ideas.

Or something they had just done, their new

Having come from Toronto, what did you learn about methodology
when you got to Columbia that was different?

Schawlow: Well, let's see. It wasn't really qualitatively different. I
was able to work longer hours because I lived right near there
and had no family.

My lab was next to the molecular beam lab. In fact, right
next door was Alan Herman, who later became chief of research
for the Naval Research Lab. We would oftenmost of them would
start work at noon and work until midnight quite regularly, so
I kind of got into working those hours too. I'd work long
hours, do a lot of chatting.

It was amusingwhen I went to Bell Labs I noticed a big
contrast. It was 8:15 to 5:15, and there wasn't much fooling
around. There was a pause for afternoon tea for the small
solid state physics group, but otherwise people were working
hard all the time. You can do things in different ways. I was
impressed by the graduate seminars, the group meetings

Riess: The theoretical seminars?
Schawlow: Well, those too.
Riess: At Columbia?

Schawlow: At Columbia. They had group meetings where different students
would discuss what they were doing, or some particular aspect
that they'd been asked to look into, some new development. We
did that at Toronto too, so it wasn't really all that
different. I think the level was higher, there were perhaps
better students.

Looking for OH

Riess: Were you at all tempted to go off in other directions in that
new arena?

Schawlow: Not really. There wasn't much opportunity. Unfortunately I
got tangled up in a difficult experiment which I never did
finish. Charlie had me, in the last six months or so, work
with some others so I'd get some publications done. I was
working on trying to find the spectrum of the OH radical, that
is, a fragment of a molecule. He was interested in looking for
it for astronomy, and indeed the OH radical was found much
later on and in astronomy it's quite important in studying
nebulae. I was a little out of my depth there, but it's
interesting, that was where he was interested in at that time,
and that's why he put me on it.

Riess: I cannot imagine the patience involved in working on something
where it might take years before you see the thing you're
looking for.

Schawlow: There's a lot of drudgery in experimental physics. You have to
get pumps and electronic equipment and everything working. You
try and fix one thing and then another, and well--. So we
didn't work as consistently as people at Bell Labs did. We'd
spend a good bit of time chatting with other students. That
was interesting, you learned some things that way, but--.

Riess: The results Mike Sanders got were a fluke? [See pp. 75-76]

Schawlow: Yes. Whatever it was happened to the discharge, I guess maybe
you had to adjust the pressure of the water vapor.

Well, we tried all kinds of things to try and get the
result. We tried looking at the chlorine dioxide, which is
another radical, but that spectrum was extremely complicated,
we couldn't make anything out of it. We saw lots of lines, but
not the OH line. It's frustrating, it certainly is. But- -I
don't know, you keep trying to get ideas to try this, try that.

I don't remember all the things we tried, but they didn't
work-- [laughs] at least they didn't get the desired result.

As I say, we spent some time looking at chlorine dioxide,
trying to get the quadropole coupling of chlorine isotopes. So
that took some time, and we sort of had results in that we saw
a lot of lines, but we didn't really because we couldn't
decipher them, there were so many lines.

Riess: Were you counting the lines or did you have equipment that
could do it for you?

Schawlow: We had a scanner. There was a dial on the power supply knob
that was connected to a clock motor and slowly turned the
thing. And you had a chart recorder that showed the intensity
of the signal. You should get a change when you go through the
right wavelength, the right frequency for that particular
absorption.

There was one amusing incident. Another graduate student
worked with us briefly when he was just starting out, named
Wilton Hardy, and we came back one day and he had chart paper
all around the room. He had hundreds of lines. But it turned
out that what happened was that the clutch on the motor was
slipping and was just drifting back and forth across the same
line.

Riess: Do you have to be taking notes when you're doing this kind of
work?

Schawlow: No. Not really.

Riess: In order to know what you've eliminated?

Schawlow: No, I think we just know what doesn't work. You preparedit
took a lot of time to try each thing. You didn't just go in
there and do something. You might work for weeks to get ready
for this particular variant of the experiment.

Riess: When you were talking about your own dexterity

Schawlow: I haven't got any. [laughs]

Riess: --you told how you were able to tune the one-tube radio.

Schawlow: That's one thing I've learned. I'll show you here how I do it.
[moves over to hi-fi equipment] I'd put my thumb and finger
here and I'd push them against each other and make the fine
adjustments.

93
Riess: But dexterity is not needed for setting up these experiments.

Schawlow: We were looking for something on the chart recorder that was
reproducible- -

Riess: It can't be dependent on--

Schawlow: It wasn't dependent on dexterity, not at all.

I might mention here that Gerhard Dieke, who was the head
of the physics department at Johns Hopkins University around
1960, told me that R.W. Wood, who was his older colleague and
was a very famous man for his beautiful experiments, was so
clumsy in the laboratory that he had to design these things
cleverly enough so even he could run them. [laughter]

Riess: Have you other stories of the Columbia years?

Schawlow: One story. They allowed me to join the faculty club there, and
to eat lunch there, and since I didn't have any other place to
eat I did eat there very often. At that time they didn't have
a lot of post-docs, there were only one or two others in the
department, so they didn't mind me sitting there with the
professors, and that was very interesting, to hear some of
these discussions.

[laughs] I may have recounted in the introduction to
Charlie's oral history, about the time they were discussing
this magazine article about the top young scientists. 1

'"Another occasion, when I was at lunch in the Columbia Faculty Club
with Charles and a few of his colleagues, the discussion turned to two
articles which had just appeared in Fortune magazine. The science editor,
Francis Bello, had picked ten outstanding scientists under age forty in
universities, and ten in industry, and had tried to draw conclusions about
what they had in common. One thing he noted was that they were all oldest
sons or only sons. Charles remarked that it didn't seem right for him, for
he had an older brother and two older sisters. Thereupon Rabi squelched
him by saying, 'You didn't make the list, did you?' There can't have been
many lists since then of the outstanding scientists of the twentieth
century that failed to include Charles Townes." [From Arthur L. Schawlow 's
introduction to Charles Hard Townes, A Life in Physics, ibid.]

The Subject of Equipment

Riess: Now, Columbia had a radiation lab group in the physics
department. Were you a member of that?

Schawlow: Yes. It had been a microwave lab during the war and they had
developed what was known as the rising sun magnetron there.
And they still had a group working on magnetrons, trying to get
shorter wave lengthsmillimeter waves. That was one of the
things that attracted Dr. Schulz of the Carbide and Carbon
Chemical Company to Columbia. That was two floors; the tenth
and eleventh floor were radiation lab. And they had an
administrative office that handled contracts and things like
that. They had a workshop and an electronic shop too.

I was on the tenth floor most of the time, that's where my
lab was. But I would go up there, I guess to order something
or to get something made in the machine shop. There was a lot
of equipment around there, a lot of microwave equipment. That
was different from Toronto. There was all sorts of --waveguide
and klystron tubes which were war surplus stuff that Charlie
had acquired, and others I guess there. Willis Lamb also had
experiments in the radiation lab.

Riess: Sounds like it's important to associate yourself with wherever
there's money so you can get equipment.

Schawlow: I suppose so. There were strange things thereas I say, we
really lacked a spectrograph which I needed, optical
spectrograph. And when I came to Bell Labs it was sort of a
shock again, because although they had huge amounts of
equipment, they didn't have what I needed, they didn't have
equipment for what I was going to do. Whereas at Columbia, I'd
gone in there and it was suggested that I work on microwave
experiments to detect OH, and they had a lot of wave guide
stuff.

They didn't have anything for what I was going to do at
Bell, and they also had this very strange regulation that you
couldn't buy any new capital equipment unless you could junk
some old equipment. And of course being new, I didn't have any
old equipment to junk. I had to hope somebody else in the
department did. The excuse for that was Bell Labs was set up
as a nonprofit corporation, and if they increased their capital
by acquiring more equipment, then that was the equivalent to
making a profit.

Now after I'd been there about five yearswell, to show
how bad it was, you couldn't even buy an oscilloscope. You

could buy a thousand dollars worth of platinum and throw it
away tomorrow, but not a three hundred dollar oscilloscope. I
felt quite frustrated by that. After I'd been there about five
years they suddenly realized that they could buy new equipment
if they say it's not for general use but for a particular
experiment. All of a sudden the purse opened and you saw big
Varian magnets sprouting all over the place and all sorts of
big equipment. I saw that my productivity shot up and so did
everybody else's. Management realized that. We hadn't
realized how much time we were spending working around the
limitations of equipment.

Riess: That's very interesting.

You've mentioned Schulz and we've talked about him before,
but this reference to his memo in August 1945 about induced
resonance, is that like he was having an idea of a maser?

Schawlow: No, he didn't have any idea of a maser. It was not induced
resonance. I think it was that you could control chemical
reactions somehow by using some radiation longer than visible
radiation. Photochemistry is well known, it goes on every day
in camera film, when light falls a chemical reaction takes
place. And there lots of other reactionsbleaching, for
instance--.

But his idea was that you might be able to control chemical
reactions if you had some radiation in between microwaves and
visible, so that was why he supported the Columbia Radiation
Lab. He knew they had the magnetron work, so they were
producing shorter wavelengths, and he knew that Charles Townes
was working on interaction between microwaves and molecules.
But he didn't have any ideas as to how to go about that. As a
matter of fact, the way things have worked out, the possibility
of chemical reactions was in our minds when we were working on
the idea of a laser. Although it wasn't really an important
motivation, it was something we hadn't forgotten.

Infrared has not been useful for chemical reactions as far
as I can find out. You irradiate them but then they tend to
quench too rapidly, they don't hold the excitation long enough
to undergo a reaction. Also, the radiation is masked by the
thermal radiation which is present all the time and is in the
infrared even at room temperature. So that hasn't really
worked out.

Riess: Charlie is still interested in the infrared.

Schawlow: Oh, yes. He's interested in the infrared for astronomy, but I
don't think he's ever done anything on photochemistry, not as

far as I know. We did for a while, and we'll come to that, at
Stanford, but we used visible light and it wasn't very
successful. There are a lot of things I didn't know.

Nepotism Issues Motivates a Job Search

Schawlow: Columbia had very strong anti-nepotism rules at that time. And
if I was going to marry Charlie's sister, then that would be
nepotism. There was never any possibility of staying on at
Columbia in a permanent way at all, or even probably not at
all. The second year, 1950-51--the Carbide and Carbon
fellowship was only good for one year, and Ned Nethercot came
in from Michigan and took over that.

Charlie wanted me to stay on to help him write this book on
microwave spectroscopy and he found some money from the Ernest
Kempton Adams fund at Columbia University to pay my salary,
same as I'd been getting on the fellowship, I think. But it
meant that it was a busy time. I was still trying to get
somewhere with this research, and he did have me work with
other students so I would have a variety of experiences and get
some publications.

It was a pleasant time. As I think I said last time, I had
started looking around, thinking that I might like to find a
wife. And then, of course, Aurelia came around and I was in
the mood. Well, she was very attractive. She was pretty, but
the main thing about it was she was intelligent and, well, the
kind of person I'd like to live with. That was really the most
important thing for me. I never had bothered with girls at all
before that. I just felt I couldn't afford to, either the
money or the time. As I say, I did look around a bit, but I
didn't see anybody I really wanted before that.

So we began seeing each other in the fall of 1950, and I
think in January we became engaged and married in May.

Schawlow: It was a busy year. I did get a letter from Professor Henry
Ireton, who was sort of the administrative director of the
physics department at Toronto, asking if I'd be interested- -no,
I'd gotten that before that year started- -whether I'd be
interested in going back there as an assistant professor, but
I'd already promised Charlie that I would stay so I didn't get
that job.

Riess:
Schawlow:
Riess:
Schawlow:

Then when I started looking for jobs in the spring, there
weren't many. Whereas in '49 there'd been a great scarcity of
people, in '51 there didn't seem to be academic jobs. There
was the complication that Aurelia had come to New York to study
singing with a teacher, Yves Tinayre, and she didn't want to
leave the New York area, so that limited things. I think I
wrote to a couple of universities but I didn't find anything.

Then Bell Labs had a very good, efficient recruiting
scheme. Sidney Millman, who had been one of Rabi's students, I
think, was then department head at Bell Labs, and was
recruiting. He'd come and talk with the professors, ask who
might be a good prospect. Somehow he suggested me.

I still wanted to do some real physics, so I was really
rather afraid that I'd just get into some kind of routine
engineering development. But what they offered me was to work
with John Bardeen, to do experiments. Bardeen had already
invented the transistor, or had been co-inventor, and had
published a lot of theoretical papers. He was a theorist and
he was beginning to get interested in superconductivity, so
they wanted somebody to do experiments on it, and they hired me
for that, even though I had no background in low temperatures
or solid state physics at all.

Now maybe that's what scared him away, but by the time I
arrived in September, he had gone, decided to go to the
University of Illinois. So there I was. And they didn't tell
me not to work on superconductivity, but I had to learn about
it and try and find something to do- -which was rather
difficult.

You were married in May?

Yes, that's right. May 19th.

And you were down in Washington with Charlie at the same time?

Yes, earlier, the end of April. So it was just a couple of
weeks before I was to get married. Two or three weeks. Maybe
my memory isn't so good at those things. I honestly do not
remember the incident that he ' s so fond of telling about how we
shared a room. [laughter] It's plausible, because indeed I had
been used to sleeping late, working this noon to midnight
shift. So it's possible that he woke up early and went
outside.

I don't remember sharing a room with him, but I can't
really deny it--but I just can't confirm it either. I never
heard about that until 1959, just before the first Quantum

Electronics Conference. He held a party in New York for the
various people coming to that conference including the two
Russians, Basov and Prokorov. That's when I first heard that
story about the park bench.

Riess: But you did witness his notes?

Schawlow: Yes, I did witness his notes. I'd forgotten that too, so I'm a
real forgetter. [laughter] I remembered him telling me about
the idea. What I didn't remember particularly was signing his
notebook.

Riess: Do you remember the electricity in the air?

Schawlow: It was an interesting idea, I thought, yes. You couldn't be
sure it would work, or how difficult it would be to make it
work, or how useful it would be. But if I hadn't been going to
Bell Labs, I would 've liked to work on that. That would have
been a good project.

Riess: Well that's really what I was thinking about. I never have
heard of nepotism that has to do with the wife being--

Schawlow: --the relative. Well, Charlie is a very upright person, very
correct, and I think he pointed that out to me.

At the time I didn't feel I was good enough for Columbia,
to tell the truth. I didn't have as strong a theoretical
grounding as I should have had, so I wasn't too concerned about
that. I think now that I probably could have stayed on there,
otherwise.

When I was talking about staying the second year, Polykarp
Kusch was the chairman, and he came around and asked me if I'd
like to be an assistant professor. That would be in 1950,
before the 1950-51 academic year started. And I had to say
that I really couldn't see how I could manage to do research
and write on the book and still do some teaching. Well, he did
offer me that, if I wanted it, and he might have offered me
something in 1951 too, but--.

More on Writing the Microwave Book

Riess: We will get you to Bell Labs, but this business of writing that
book-- .

Schawlow: Ooh, horrible job.

99
Riess: You tell me why it's a horrible job.

Schawlow: To begin with, 1 didn't know anything much about microwave

spectroscopy. I'd only worked on it really for a year. Well,
we divided up different chapters, and I had to draft some of
the chapters and Charlie drafted the others . All the more
complicated things he did, and the things I did he revised
pretty heavily. But it was a lot of learning. I had to read a
lot of papers and try and boil it down into understandable
prose. We were writing about basic principles, and also
reporting on what had been done.

I felt when we started on it that if I was going to do it
at all, I really want it to be a classic. And I think it is.
It's still in print and has been referred to many, many times.
So I was willing to dig fairly deeply in the stuff. There was
a review of the basic theory: you had to do molecular theory
and microwave theory, and I think we even had a chapter on
atomic physics to bring the thing up to the start. Then a lot
of the detailsCharlie did a lot of detailed stuff on the
interaction of microwaves with molecules, and that can get very
complicated, particularly if you get asymmetric top molecules
that have little symmetry.

Of course, my attitude about molecular spectroscopy up
until then was given by a definition that I've repeated many
times: that a diatomic molecule is one with one atom too many.
[laughs] It can get very complicated, and here they were
dealing with atoms that actually had even more than two atoms.
So I had to read a lot of theory and try and put it in
understandable form.

After I think about eleven chapters or so on the
spectraand they would be illustrated by reports of
experiments that had measured certain things there--. The
bibliography had a thousand and one references. Actually, it
was a little over that, but we put in some "a's" and "b's" so
we'd come out a thousand and one.

Then after that there were several chapters on microwave
techniques and one on millimeter waves--! remember I drafted
that one. Of course, millimeter waves were not very advanced
at that time. They were beginning to be used, but I remember I
started the thing off saying something about their difficulties
but techniques nevertheless are now available. And there was a
misprint in the book, and it came out that "techniques are not
available." The editor from the publisher said they expect
about one error per page on a technical book like that, and we
had the manuscript read by several graduate students and still
there was about one error per page.

Riess:

Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

Riess:
Schawlow:
Riess:
Schawlow:

100

Maybe they were just predisposed to thinking they were not
available.

Well, anyway, that's the kind of thing where Spellchecker won't
help.

I once put a speech synthesizer in my computer that would
read text that you have in there. And I caught a mistake
there. I think I had and "of" instead of an "or." I haven't
done it since then, but it seemed like a useful idea.

Did you have any trouble with the writing?
write in general?

Do you struggle to

Yes, I do struggle. I used to think I could write pretty fast,
but I couldn't. And when I do a draft or something I tend to
cross about every second or third word and keep struggling with
it. Usually, though, when I'm through the first draft, I'm
through, because I've done my revisions as I go along. I guess
now I'm probably doing a little more revising, but generally
the first draft is a struggle.

For the spectroscopy book, did you write it by hand?

Yes. It was all by hand. I did have a typewriter at the time,
but I think Charlie's secretary did the typing, I don't
remember typing any of that. Of course, there were a lot of
mathematical symbols.

I remember one thing is that when I was a student the
people teaching electricity and magnetism used the centimeter,
gram, second system of units--cgs, those were the basic units.
But the engineers foisted on us the mks system, which is meter,
kilogram, second. Let's see, now, we wrote the chapter on
microwave techniques first I think in mks. Then we decided
that physicists were more comfortable with cgs. And then we
were persuaded to go back again and translate it back, which
was a certain amount of bother. [laughs] I think we ended up
with the mks system. The engineers were the ones who pushed
the mks, but the physicists had given up on thatmostly, not
entirely.

Who were you writing the book for?

McGraw Hill.

For the engineers or the physicists?

Well, physicists and chemists mostly. The mks system had been
accepted by national standards bodies, and we were told it was

101

Riess:

Schawlow:

Riess:
Schawlow:

Riess :

Schawlow:

Riess:
Schawlow:

supposed to be the system of the future. We wanted to be
understandable, so that's the way we ended up.

Well, all things considered, 1951 was a big year. You decided
to stay and work on the book, not to go back to Toronto, for
instance. And you are very identified with the book?

Well, clearly Charlie is the senior author on that, and he's
gotten at least one award for it, but yes, it helped me a lot,
helped my reputation quite a bit, because it is a formidable
book even though I didn't write it all. But for me personally
it was a waste of time, because I haven't worked on microwave
spectroscopy since then. I practically never looked at the
thing again but it was good advertising.

You were working on that when you were at Bell Labs.

Yes, it went on and on. I would go in practically every
Saturday to Charlie's office to work on it. I guess I worked
on it some at night too. I finished it I think in '54. It
takes some months to actually get it into print, but it came
out around June of '55, May or June.

Not an ideal way to start out being married,
much more like a graduate student.

That's living

Yes, it wasn't an ideal way to start a career at Bell Labs
either. It was distracting. I could 've done better. You
know, we managed. Aurelia was understanding. I didn't do much
writing at night, actually. It was mostly just Saturdays I
would spend on it.

Oh, we had tickets for chamber music concerts in New York,
and quite a few Saturdays I would go into New York in the
morning, and come back home at around noon or so, and then go
into New York for the concert in the evening. I remember being
rather sleepy during chamber music concerts.

Did you pursue your interest in jazz or did marriage end that?

Well, kind of dampened it a bit. I didn't really pursue it
seriously at that time. There was a hiatus for a few years. I
picked it up again when we came west and I had more room to
store records.

102

III BELL LABS TEARS

Experiments on Superconducting Phenomena

Riess: Let's talk about your work in superconductivity at Bell Labs.

Schawlow: Well, I did some cute things. They didn't solve the problem of
superconductivity. Bardeen, Cooper, and Schrieffer did.

Riess: Were you the point man on superconductivity at Bell Labs?

Schawlow: Superconducting phenomena. I should explain that Bell Labs
seemed to want to cover a lot of fields. They said that the
purpose of research there was so that they would be informed
about the latest developments that might affect their
technology, and they felt the best way to do that was to have
people working in the different fields. It wouldn't do any
good to have somebody sitting in the library and reading stuff
because that would be a year old. But they wanted people to go
to meetings and discuss on an equal level with others in the
field so that they would really know what was going on in the
frontier.

I was the only one working on superconducting phenomena.
Bernd Matthias was working on superconductive materials. He
was sort of an alchemist. He mixed together all sorts of
things, worked very intuitively, and he did find some new
superconducting materials, and ferro electric materials too.

Hal Lewis did some work on the theory of superconducting
phenomena. I had the feeling about superconductivity that it
was such a perfect thing that it was awfully hard to get a
handle on it. I mean, the electrical resistance is really
zero, not just nearly zero. Magnetic fields just don't
penetrate. Well, we did do experiments where it had been found
that magnetic fields do penetrate a small distance sometimes,

103

something like a few hundred to a few thousand angstrom units,
an angstrom being 10~ 8 centimeters. Oh, I'm showing my age: it's
10' 10 meters. In fact, you're not supposed to use those units
any more. You're supposed to use nanometers, a nanometer being
ten angstrom.

Anyway, that's a small distance. But one of the
experiments I did was to measure the penetration depth by
winding a coil very closely around a rod of superconducting
tin. And you can get very pure tin, it was surprising. You
could buy it from a company called Vulcan Detinning. It turns
out that people do recover the tin from tin cans. And there's
not much on a tin can, so they have to have extremely selective
processes which take the tin and nothing else. So you can get
tin that's extremely pure, and so we got some and made up a rod
of it. We wrapped a wire coil very closely around it. In fact
we wrapped it around the inside of a glass tube. I used to kid
people, say that I did it by a simple application of
centrifugal force, but in fact we had it wound first.

Bell Labs facilities were very useful there. We got
niobium wire enameled, coated with Formvar, which is something
you couldn't buy on the market but they prepared it for us.
Then they wound it on a mandrel, on a rod, and it was just the
right diameter. Then it would be cemented together with this
Formvar. Or rather, they'd put some kind of cement on it and
slip it inside a glass tube and then remove the mandrel. Then
you put the tin rod in place of where the mandrel had been. It
was a close fit.

What we did was to measure the inductance of a coil which
depended on the amount of magnetic flux inside it. Well,
magnetic flux depends on the magnetic field and on how much
space there is. And the volume was small, just the space
between the rod and the coil, and whatever penetration distance
there was. So what we could do was measure the change in the
penetration depth as it cooled it through the superconducting
transition. We did that by making this coil part of a radio
frequency oscillator, and then the frequency of the oscillator
would change, and we had a crude frequency counter which were
just becoming available, and we could measure the change in
frequency.

It turned out that--. This was not the first thing I did,
it was more like 1957 I think. But we found a departure from
the predicted dependence on temperature. The penetration depth
fell out more rapidly as we cooled it. These were small
effects, but we were able to measure that the penetration depth
changed more rapidly than the simple theories had predicted.
And it turned out that this was also a prediction of the

104

Bardeen, Cooper, Schrieffer theory which came out about the
same time. Bardeen asked me to present these results at a
conference that he was organizing. And so that was useful. It
helped to confirm the BCS theory, but it didn't really open any
doors.

We did another experiment earlier where we used penetration
through a thin film, and there I really missed something. What
we did was have a thin film coated on the inside of a glass
tube, and then put a tiny little coil inside it to pick up what
signal could get throughwe'd have another coil outside with
an audio frequency signal and pick up the signal and measure
how much it was .

We got some results which were reasonably consistent with
other measurements of penetration depth, but we noticed that
there were spikes sometimes coming through suddenly. Hal Lewis
suggested that maybe it was flux quantization, which would have
been a great thing to discover. But we didn't take it
seriously. We thought it was associated with defects in the
film because you got it some places, not others. But that's
exactly what we should have expected would permit flux quanta
to penetrate through. So we could have discovered quantization
of magnetic flux in superconductors, but missed it.

Riess: How big a deal would that have been? Is that something
somebody discovered later and got a big Nobel Prize for?

Schawlow: Well, unfortunately not a Nobel Prize. My colleague at

Stanford, William Fairbank, discovered it about the same time
that I came, in a different way. He should have had a Nobel
Prize for it, but it was discovered independently in Germany by
R. Doll and M. Nabauer, and then Nabauer died a few months
later. So I think maybe that's why they didn't give a Nobel
Prize for that. I think he should have had it, I nominated him
for it.

The reason why it was interesting was because the flux
quantum was only half of the value that people had predicted.
The value was hc/2e. That is, it depended on two electron
charges--h, Plancks constant, divided by 2 times the electron
charge. Now the reason that is important is because the
Bardeen, Cooper, Schrieffer theory depended on pairing of
electrons. So pairs of electrons get coupled together and
provide the superconducting current.

That could have been an important thing. Now, wait a
minute, the BCS theory was already there, not from when we did
our experiments but when Fairbank and Deaver--who was a
student, Bascom Deaver--discovered the flux quantization.

105

Still the fact that it was hc/2e was a useful new piece of
information. It surprised a lot of people.

Riess: When you were working on this, who would you report to? How
was it set up at Bell Labs?

Schawlow: There was a department head, a man named Stanley Morgan. He

was a chemist. He was a good administrator. He had been joint
head of the solid state physics group with Bill [William]
Shockley, but Shockley had been an impossible person to get
along with. They had split the group, and Shockley had a group
on transistors, and the rest of solid state physics was under
Morgan. Although he was a Ph.D. physical chemist, he didn't
really try to tell us what to do.

I remember that one of the technicians there, quite a good
man named Ernie Corenzwit, went to Stan Morgan one day and
asked him when should he ask about what to do. And he said
Morgan told him, "If you know what to do, do it. If you don't,
ask." I thought that was a good philosophy. In fact, when we
came to Bell Labs they had indoctrination sessions. One of the
men there told us, "The first thing you've got to learn is
there are no oracles. You'll have to think things out for
yourself." So they didn't interfere much with that.

Earlier I had done some nice work on the interface between
superconducting and normal regions. Although it was a cute
idea, I don't think it was really important. When a magnetic
field penetrates into a slab of superconductor, if the field is
perpendicular to the slab, then it comes in in regions. And
some regions are normal where the magnetic field has penetrated
and destroyed the superconductivity. And the regions in
between them remain superconducting. This is known as the
intermediate state. There's been a lot of speculation about
that and you could measure the surface energy of these
boundaries.

Well, what we did was to sprinkle niobium powder on the tin
plate and photograph it. Niobium powder is superconducting and
it's pushed out of magnetic fields, unlike iron filings which
would be pulled into a magnetic field. But the niobium powder
is pushed out, so you saw a nice pattern of the lines of spaces
on the thing.

And we got several papers on that. We did it first, I
think, with polycrystals and then we did it with single
crystal. Then we were very surprised because the magnetic
field penetrated faster in the direction that we thought was
the wrong one because the higher the conductivity, the more

106

dampening it would be, it would slow down the motion. But it
came in the direction where the conductivity would be higher.

This worried us a great deal. In fact, Bob Schrieffer was
a graduate student, one of the people who did this, later got a
Nobel Prize for the theory of superconductivity. He spent the
summer there. And Hendrik Gorter from Holland was there, and
nobody could explain it. But then I did a measurement of the
magneto-resistance of this very pure tin and I found out that
by the time you reach the field of a couple hundred gauss,
which breaks down the superconductivity, the magnetoresistance
has crossed over, and the direction which was high before
became low.

Your picture it like this: look at my hand here. If I put
a magnetic field perpendicular to that, then the field would
penetrate in there and I would see these lines. If you have a
square plate, you couldn't tell which way it was going to come,
it would come in from all the edges, but it comes faster in the
direction where the resistance across here is higher because
that doesn't dampen as much.

Schawlow: As I say, then we did this experiment to measure the

magnetoresistance, which is hard to because these things are
extremely good conductors even in the normal region--this was
very pure tin, I think it was something like a hundred thousand
times lower resistance than at room temperature. So again, I
did an experiment where I wrapped a coil around the thing and
measure the inductance, and that gave me the resistance. I'm
pretty good at putting coils around things, [laughter]

Riess: You talked about Bernd Matthias and other people. Was this a
team that was working together and constantly talking?

Schawlow: No, no, absolutely not. Matthias was strictlyhe was a very

intense sort of person, and he was extremely original. In Bell
Labs I gather he used to wear no socks a lot of the time, was
considered one of the wild men around there. When he would
rehearse a talk--. They would get you to rehearse your talks
at Bell Labs, which was very good thing. It's one reason Bell
Labs people had a reputation for giving good talks. But he
would be outrageous, he would say horrible things, and then
when the actual date came he would give a good talk. But he
just liked to put people on.

For a time we shared a laboratory with him. Now he
wouldn't do anything as far as the experimental equipment was
concerned. He had collaborated with John Hulm, who was at

107

Westinghouse, and Hulm had given him a design for a cryostat
where he could test his samples. All he would do washe might
have Corenzwit make up some samples, using electric arc melting
usually. Then he would bring them in and lower them one by one
into this cryostat, and check whether there was superconducting
or not. That was in the same room that I had my apparatus, but
it was a simple rule that when he was there, I wasn't.

Research, Resources

Riess:

Bell Labs didn't work in teams?

Schawlow: They didn't work in teams, not in the basic research.

The one thing I didn't realize for a long time--. I really
didn't make use of the resources. The way things happened at
Bell Labs was Mr. A gets an idea; he goes to Mr. B who makes a
sample for him; and takes it to Mr. C and D who make
measurements; and then to Theorist E; and they come out with a
paper with five names on it. And they say, "Oh, Bell Labs has
put a big team on this," whereas generally by that time,
they're not even speaking to each other.

I didn't realize that there were a lot of lonely people,
like myself, sitting around, and they have equipment for
something or other. If somebody can think of what could be
done on that equipment, they can drop what they're doing and
help you. It was very good. Both the experimentalists and the
theorists too would help each other when you asked them. But I
was too shy to ask them most of the time. The last few years I
did begin to work with others.

Riess:

Schawlow:

How did you get from one problem to the next?
that something was done?

How did you know

You read. To begin, there's a book by David Shoenberg, from
Cambridge, on superconductivity. I read through that and
looked for ideas, and that's where I got the idea of measuring
penetration depths. Then, well, I talked a little bit with
Lewis, even Matthias very occasionally would talk. In fact he
had the idea of looking at the intermediate state by sprinkling
iron powder on the thing, and the iron would be pulled into the
regions where the magnetic field had penetrated. I persuaded
him that it was better to use the superconducting powder that
would stay away from the regions where there was a magnetic
field. Now I'm not so sure that really was better, but it
worked.

108

Riess: I'll give you a break and read some of the Bell Labs philosophy
on doing basic research: "...[research] deals constantly with
uncertainty, except that there is ever present the certainty
that important new things remain to be discovered..." 1

Schawlow: And there were not very many people in research, maybe a couple
hundred people in the whole place out of about seven thousand
altogether.

Riess: "...[research] must assure the flow of invention and new

science that will enable future technologies to be developed.
And it must see the ways this invention and new science can be
exploited by Bell System."

Schawlow: Yes, well, maybe not right away. A lot of their research was
more closely tuned to communication needs.

I used to worry sometimes because I couldn't see why what I
was doing was going to help the Bell System at all. But there
were people doing communication research. Oh, for example, the
satellite communication, they pioneered that, first with
reflecting balloon satellites. Oh, they developed the
travelling wave tube there and things like that, which were
research but they were more directed toward the needs. But
ours was just basic physics, not all kinds of physics, but
physics of materials and things that were related to the kinds
of things they did.

But the inventions that came out of our department, I
think- -there were few, and they didn't expect many from the
basic research. And they were very expensive. Things like
transistors and lasers took millions of dollars to develop
because they were so far out before they could get any use from
them.

Riess: Where else was similar research going on?

Schawlow: There was work at Columbia, and at Rutgers too. I guess we

knew what they were doing, what they published, but it wasn't
very close to what we were doing. About the only people doing
things close to what I was doing were a couple guys in England
and in Russia. Maybe I hadn't chosen very well, but it felt
rather isolated.

We did do one useful thing for Bell Labs which maybe paid
for our salaries during that time. I think it was Dudley Buck

1 xv, A History of Engineering and Science in the Bell System:
Physical Sciences (1925-1980), AT&T Bell Laboratories, 1983.

109

Riess:

Schawlow:

at MIT who invented a superconducting switch that you could
make switching systems orcalled a cryotron. You could in
principle make computers or even telephone switching networks
from that.

So they had a meeting. IBM put a lot of people on it, I
don't know, maybe a dozen, or twenty. They tended to throw a
lot of people at problems. They did that on ferro-electric
memories before that, and then they sort of worked for a couple
of years and gave it up. I'm told that Watson said, "There's
so much money to be made in computers that we can't afford to
overlook anything." And that was true in those days.

So they had a meeting to ask should we at Bell Labs get
into cryotrons. Lewis and I went there and pretty easily
persuaded them that they shouldn't. And indeed nothing did
come of it at that time. There were two reasons: one is that
it had to be in liquid helium and, well, it was primitive and
not very fast either at that time; the other thing is that
while you might use it for computer calculations, it wasn't
suitable for the telephone system where you're switching. You
need a lot of input and output, so you had to have a lot of
wires coming in and out of the low temperature region which is
very hard to do, because they conduct heat. So anyway, we did
tell that it wasn't worth getting into and I think saved them a
lot of money.

Just because one part of the word is the same,
and semiconductors are not.

superconductors

Riess:

Schawlow:

Riess:

They're worlds apart. They're both solids, but--. And I
didn't work on semiconductors.

Shockley would have liked me to work for him I think, but
Charlie had warned me and so I didn't go to work for him.
Charlie said, "He's nice, but if he thinks you're a rival, he
can be pretty hard." I don't know whether you know his history
here in California but he started the Shockley Semiconductor
Lab which was financed by Beckman. And he hired some very good
people, but then they went off and started other companies:
first the Fairchild Semiconductor Company and then a lot of
others, National Semiconductor and maybe Intel. He was so hard
to get along withhe knew good people, he had high standards-
He inspired an industry.
Oh yes, he did, he was very important.

Inspired it by people wanting to get as far as possible from
him.

110

There's a whole list of things that were developed while
you were at Bell Labs. High temperature superconductivity was
one of the things, though somewhat earlier, between 1951 and
1955.

Schawlow: Oh, goodness. Well, high temperature is relative. Matthias

and [T. H.) Geballe did work on some materials and I think they
had for a while the highest temperature superconducting alloy.
I think it was niobium germanium. It had transition
temperature of around twenty degrees Kelvin, so you could
actually run it in liquid hydrogen rather than liquid helium.
But that ' s nothing like the high temperature superconductors
that were discovered in the 1980s. They go up in temperatures
over a hundred degrees Kelvin. They can be run in liquid air
which makes a big difference.

Let me be fair with them there. This materialwas it
niobium germanium or niobium tin? one of these fairly high
temperature superconductorscould also resist magnetic fields
better than others, so that you could wind a magnet from it.
Now if you wind a magnet coil from superconducting wire and put
a current through it it produces a magnetic field, but when
that's strong enough, it destroys the superconductivity. These
could resist that, so these wires are still used for
superconducting magnets which are used quite widely in magnetic
resonance imaging devices.

So the high temperature wires, they were important- -even
though I wouldn't call it as high a temperature now. For those
days it was high, and those are still the best for the magnets.

Murray Hill and the Work Day

Riess: Let's just get you situated a bit now.
you were?

Murray Hill is where

Schawlow: Yes. It was a little town, almost nothing there except this

huge Bell Labs laboratory at that time. I think now it's been
built up quite a bit around there. It was out in the country
pretty much, west of Summit, New Jersey. The nearest town was
New Providence. There was a Murray Hill post office, I think,
which was the largest second-class post office in the country
or something like that because of all the Bell Labs system.

Riess: I want to make sure that we really get an idea what is was like
to work for the Bell Labs, what the virtues and the drawbacks
were, and how you could ever be induced to leave.

Ill

Schawlow: It wasn't hard.

Riess:

Schawlow:

Riess:

Schawlow:

Charles Townes spent time trying to get them to do things that
they were so slow to think about doing.

I was shyer, probably. I didn't really particularly try to get
them to do things. I could have and should have. Like, for
instance, when we had any ideas for lasers, I should have tried
to get them to give me some people to help me try and build
one. They didn't have anybody, and that's the way it was, so I
didn't try to build one. I just sort of assumed it wasn't
possible.

I worked conscientiously, but I didn't work much at nights,
only very rarely went in at night or on weekends . I spent a
lot of time with my wife and then family. It was sort of like
a job. I mean, it wasn't as consuming as it has been at the
university. Of course, the university, you have teaching and
administration, all added on.

It sounds like they set it up to make it just like a job, if
you've got to be in the parking lot at eight--

Eight-fifteen, yes, at the beginning. Yes, I think so. It was
an industrial company, really. They changed that. About the
last couple of years I was there, maybe the last three years or
so, they decided they were going to make more spread in the
salaries and they would have formal evaluations of people.
They would divide them into octiles, the best eighth and so on.
Well I don't know how my rating was, but I don't think it was
very high because I was working alone on superconductivity, and
no great invention had come out of that.

At one point Hal Lewis and I asked the boss if we should
write down some ideas. We could think of inventions, like
switches and so on. He said, "Well, does it have to work in
liquid helium?" I said, "Yes, I guess so." And he said, "Well
then don't bother." So we didn't bother.

As I say, I think they really didn't think very highly of
me because they made me the department safety representative,
and that's usually a kind of drudgery job that they give to
somebody who isn't doing anything else much. About the only
thing I did was that I had to write an accident report when one
of the theoretical physicists stabbed himself with a pencila
sharp pencil. I pointed out that theorists should be
instructed on the uses of pencils [laughter].

Riess:

Another thing you did was teach while you were there,
taught a class on solid state physics.

You

112

Schawlow: Yes, that's sort of ridiculous, but they asked me to do it and
I did it. I learned solid state physics as I went along. It
was kind of fun, but it was work. I had to go to New York for
those [lectures], three days a week I think it was.

Riess: You mean you were teaching in New York?

Schawlow: The new engineers who were coming in. They still had a big

laboratory in New York. That was their headquarters for a long
time. People would come from Murray Hill, maybe even from
Holmdel, which was mostly military engineering. I don't know,
we didn't get to know who the students were very well.

Riess: You also built an audio frequency parametric amplifier.
Schawlow: Oh yes, just for the heck of it.
Riess: How did that fit in?

Schawlow: Well, after the maser came along, some people realized thatI
think it was Harry Suhl who realized you could make what we now
call a parametric amplifier. (I think Rudy Kompfner gave it
the name.) It's one where you change the parameters of a
circuit, namely the inductance or capacity. If you do that at
twice the resonant frequency by the circuit, then you can make
it oscillate and you can make it amplify.

I tried to learn, get my thoughts straightened out, you
know, how did this compare with masers, which I wasn't working
on, but I was interested in them. It was rather simple: you
could find in the stockroom toroidal coils, that is, with a
doughnut-like iron core. You'd find that in the stockroom and
then you put that in the circuit board with a capacitor, and
you'd get a resonant circuit. Then I would change the
inductance of that coil by wrapping another coil around
itthese are very high permeability cores, and because of that
they're easily saturated, you could saturate them on every half
cycle, or so, and so you could change their inductance. We did
that.

It was just kind of fun to make that. I think I wrote an
internal report on it, but I didn't publish anything on it. An
interesting sidelight is that Suhl had invented this parametric
amplifier that used a microwave ferrite. He didn't build it;
he was a theorist, a very formal theorist, but he could invent
things with formal mathematics .

Then he realized the generality of this concept, and they
made an application for a patent in his name, but the patent

Riess:

113

office came back and said, "You can't have that patent because
Bell Labs already has a patent"--! think it was Jacobsen, I'm
not sure, issued in the 1930s. It had just been forgotten. I
think they didn't realize that the parametric amplifiers were
low noise amplifiers and didn't realize the importance of that.

This man was still around, this guy whatever his name was,
though he was in a different department. We never met him.

Then in 1957 you and Charles Townes got back together again and
start doing things . That sounds like the place where we should
begin next time.

Madison, and Home Life

Riess: Before we finish today, would you describe life during the Bell
Labs period? You and Aurelia lived in Madison?

Schawlow: We lived for the first five years of our marriage in

Morristown, New Jersey, and then we bought a lot in Madison and
had a house built there in 1956. We were very lucky in a way:
there was a section of Madison, a very nice section adjacent to
Drew University, which had been partly developed in the 1930s
and then people ran out of money. So some lots were left in
among the houses. We were able to get one from an old couple
who had finally decided they were never going to be able to
build there. It was covered with dogwood trees, lovely, a very
pretty area--Woodclif f Drive in Madison.

Riess: And you got an architect?

Schawlow: Well, we got a set of plans from a magazine, you know these
housing magazines sell plans. Then we hired an architect to
modify it for the particular lot, adapt it to the lot. Then we
had to get bids and they were all high. But then this black
man came along, Reverend Sanders I think. Anyway, he was a
minister part-time and builder. He hadn't built a house,
actually, but he was a carpenter. He didn't do a bad job on
the thing.

We said we wanted to be able to put in air conditioning
later on, and the architect hired a heating consultant to
design the ducts for that. The builder got a heating and air
conditioning man who took one look at those plans and said,
"Those ducts won't go in those beams. They're too big." So he
said, "Leave it to me, I'll do it right." So it was sort of
architect-designed. It was a nice house, we liked it. We made

Riess:

114

one mistake. We didn't bother to have a garage. We didn't
really need it, but I think when we were selling it it probably
was a defect.

When we came to sell it in 1961--we were moving away--we
had quite a hard time. We tried to sell it ourselves but we
didn't succeed. Finally got a real estate agent who sold it
shortly after we left. But one of the big problems was that at
that time they were talking of building a third New York
airport in the so-called Great Swamp, which is near there and
we would have been right on the flight path. So that depressed
housing values at that point.

What did you like to do? Did you do outdoorsy things at all?

Schawlow: Not very much. We liked to go to concerts and shows, things
like that.

It was rather unfortunate, in a way, that Aurelia had got
this job at the Baptist church in Morristown as choir director
and organist. A wonderful man was the minister, Mr. Barbour.
She had written to several churches, and one day when she was
feeling particularly depressed he showed up at our apartment
and offered her the job, and that really made things look up.

She was a very good choir director. She had directed a
choir, choruses. She'd taught music at a college in Georgia,
Piedmont College, even put on a concert with Percy Grainger,
the composer. He came there and they played his music--! guess
he played some too. But what was unfortunate was that she
didn't know how to play the organ, although she played piano,
so she had to take organ lessons, and for the first few months
they had a substitute organist.

She had a good choir there. But that meant every Sunday we
had to be at home, we couldn't go away for weekends, which was
a limitation. And I had to work during the week. When we had
vacations, we'd usually drive up to Toronto or down to South
Carolina to visit folks there.

I guess our common interests were mainly cultural, and also
in the church, too. We got active in the church. I was on the
board of trustees and even on the deacons --which was clearly
ridiculous. It was a very liberal church, and although it was
a Baptist church, you didn't have to be baptized. And I hadn't
been, and as an adult I didn't feel like doing it. But they
still wanted me on it.

Riess:

That's why you're saying it was clearly ridiculous.

115

Schawlow: Yes. And there were young people's groups. We got some
friends there. It was a nice time and nice people.

Riess: Did you have your children by then?

Schawlow: We had trouble having children. Aurelia had to have- -what is
that test where they put carbon dioxide into the fallopian
tubes? Apparently pretty painful. But after that we had
children. Our first year or two, we thought better not to- -the
advice you usually get is don't have them too soon. But then
afterwards we were trying and not getting anywhere. So finally
we took that test and then Artie was born in 1956, Helen in
'57, and then Edith in '59. They were all born during those
years.

Riess: But for the first year she was in the apartment and depressed
and happy to be offered the job. Why depressed?

Schawlow: That was just shortly after we came to Morristown. We went to
a garden apartment complex there and they had thin walls . She
wanted to practice, and there was a woman I think downstairs
who absolutely would not allow her to practice anytime.
Aurelia tried to arrange a time when she could do it and just
wouldn't. We fortunately found another place which was the
second floor of a house on the other side of Morristown with a
nice old lady, a retired kindergarten teacher who was slightly
deaf and didn't care how much music we made as long as we
didn't do a lot of drinking- -which we didn't do.

I guess working on her career was more and singing. She
was still taking singing lessons until after Artie was born, I
know for a while after that, and was going into New York to
work with an accompanist. But that's a very tough business to
try. She had a beautiful mezzo soprano voice--! have some
recordings of herbut she never got any opportunities really
to be a singer. It's just a tough business. William Warfield
was also studying with Yves Tinayre at that time, and he's had
a successful career.

Stan Morgan and the Solid State Group
[Interview 4: September 12, 1996] I*

Schawlow: When I went to Bell Labs I went into the so-called solid state
physics group, which was headed by Stan Morgan, who had been a
physical chemist. He was a very nice person, very easygoing,
quiet sort of person, but very capable. He didn't tell us what

116

to do, which was difficult of course. I didn't know what we
were supposed to do, particularly since I was working on
superconductivity and had to find out something to do. The
group was a remarkable group and I used to wonder at that time
how many of them would be famous ten or twenty years from then.
Really, all who stayed active in physics did achieve big
reputations.

They included Walter Brattain, who had already been co-
inventor of the transistor and did get a Nobel Prize soon
after. I remember the day when he got the prize the telephone
company very quickly managed to intercept his calls somebody
would answer them for him. But he did come to our afternoon
tea, which was held every day. I remember him looking at the
newspaper and commenting adversely on some of the things it was
saying.

One of the things I remember about Brattain is really worth
mentioning. He told us his father was a prospector and was
working up in the mountains stillhe must have been fairly old
by that time. But he was several miles from the nearest store
of any kind, and they [the store] had a telephone, and the only
way to reach him was to send something to him care of this
place. Well, Walter somehow didn't want to make it too public,
so he sent a telegram saying: "Transistor men win Nobel Prize."
When it reached his father it said: "Your sister won the Nobel
Prize." [laughter]

That group included Phil Anderson, a theorist who later got
a Nobel Prize; Conyers Herring and Gregory Wannier, both very
distinguished theorists. And they were people who were willing
to talk to you if you had any questions. Conyers has been at
Stanford for some years since he retired from Bell Labs, still
active. A very encyclopedic theorist, he knows everything,
practically, and has made many important advances.

Also Bernd Matthias, who was kind of an alchemist, I think.
He kept inventing new compounds for superconductivity or
ferroelectrics. There were a few others who dropped out. John
Gait, who had done distinguished work, went into management and
later was one of the top people at the Sandia Corporation which
was then being managed by Bell Labs.

Riess: Were you all more or less the same age?

Schawlow: No. Well, I don't think there was anybody much over forty.

Well, Brattain was. They were all fairly young. Some of the
theorists I think were older- -Wannier and Herring. Anderson
was young. He's younger than I am.

117
Riess: You said Wannier?

Schawlow: Yes. He later became a professor at the University of Oregon,
[laughs] He was Swiss, and they begged him to come back to the
University of Geneva, which he did for a year, but then he came
back. He said he couldn't stand the food, it was too rich.

Riess: It sounds like one of the real pluses of working at Bell Labs
is that notion of a group.

Schawlow: But they didn't work on the same problems. You could discuss
anything and--

Riess: What defined a group then?

Schawlow: Well, they were in the same department. Yes.

There were personal matters involved. For instance,
Brattain had worked on semiconductors and co- invented the
transistor but he couldn't stand Shockley, and that's why he
was with Morgan rather than Shockley. There are many people
who couldn't stand Shockley I think, though Shockley was
brilliant.

Morgan was the head for about five years or so. He then
became head of the chemistry department, which was another step
up. They changed the title. Ours used to be known as a
subdepartment, and then there was the department, the physics
department which was headed by [S.] Millman, who was also
another easygoing guy but very capable. He had been one of
Rabi's group at Columbia before, and he was the one who
recruited me for Bell Labs. Then there was the general
department which was under Addison White.

Later they inflated the titles so that the subdepartments
became departments and the departments became laboratories, I
think. So the department head became a laboratory director. I
forget where it went from there. I remember joking at the time
that they should inflate all the titles so that the staff
members like myself should be called research executives and
the technicians would be associate research executives,
[chuckles] But I don't think they adopted it. Actually, we
were known only officially as members of the technical staff,
but I've always put in my biography that I was a research
physicist, which really was what I was but the title was just
"member of the technical staff," like all the engineers and so
on.

We also had Richard Bozorth, who was older but had a very
distinguished career in magnetic materials. I remember before

118

I came there, I read an article in Reviews of Modern Physics
reviewing magnetic materials and it apparently was also being
published in Encyclopedia Britannica, the same article, and it
was beautifully writtenand it was by Bozorth.

The custom then was that each experimentalist had a
technician working with him. I had Jerry Caruso for a while,
but he didn't like what I was doing so he switched to another
department . I had to find another one and then George Devlin
came along. Now, he had an unusual background. He was quite
young. He had never--! guess he had finished high school, but
he certainly had no college. But he had been a champion model
airplane builder, and I thought that shows he's pretty good at
building things.

He turned out to be very, very smartbut totally
nonmathematical. I tried to get him to take college courses
and go ahead, but he just couldn't manage math, not even
arithmetic. But he could think intuitively about things,
extremely well, and he noticed things that I didn't notice
about the experiments, so he was really indispensable. He
joined me perhaps around 1953 or so and was with me until the
end.

Riess: Were these people like Caruso and Devlin freefloating at Bell
Labs?

Schawlow: No, no, they were assigned to a particular scientist or
engineer.

Riess: What had Devlin been doing before?

Schawlow: Well, he was pretty young; maybe he hadn't been doing anything.
I don't know. But he really did a good job.

Riess: Did he understand the experiment?

Schawlow: Yes, he could understand experiments very well a good

understanding of physics, but in a nonmathematical way, which
actually suited me pretty well.

There were others in the group, like Ernie Corenzwit who
worked for Matthias, and was very good at fabricating the
materials that Matthias wanted made. Matthias, Herring,
Anderson, Brattain, and myself all became members of the
National Academy of Sciences. Wannier never made it, which was
really regrettable. He was on the ballot quite often, but when
he moved to Oregon he was sort of out of sight, and somehow
never got enough votes.

119
Riess: Is one elected by the entire Academy?

Schawlow: Eventually, yes, but it's a very elaborate procedure, where the
individual sections, like physics, they even have subgroups
that try and pick out nominees and the section votes on it.
The top ones in that go on to the class committee which
includes geology and astronomy, and mathematics I think.

I'm sure they must have a lot of fighting in those
committees because they have to rank order them, and then when
they get on the ballot, you have to vote for a certain number
in every class. People in other classes don't really know
anything about the candidates say in the physics class, people
in biology or something like that. So they tend to vote for
the ones that are picked out by that class as being the top
candidates. When you can get through these several filters,
you may get elected.

Riess: Would you say Stan Morgan particularly brought you along as a
group? Or is it just happenstance that all these splendid
people were together?

Schawlow: We were hired by various people.

Bell Labs had a very extensive recruiting system then.
They would have a contact at each of the major universities who
would know the professors and would go there every year and
ask, "Who are the good people coming out this year?" Millman
was from Columbia, he went to Columbia, and I guess Townes,
maybe others told him about me and so he brought me over. I
was interviewed by Ad White and by a number- -you go around and
talk to a number of people there, and finally they decide they
want you.

It was a very thorough recruiting. They [Bell Labs] had
people at Berkeley. I was recruiting at Toronto for some years
when I was at Bell Labs. You recruit not only for your own
department, but for others that are not too distant.

Riess: You introduce this by saying that Stan Morgan really didn't

tell you what to work on and that was a problem, yet somewhere
along the way in the hiring and the recruiting they must give
you a pretty clear sense of what they want you to do there.

Schawlow: They had claimed that the purpose of the research department
was so that they would be in touch with all the relevant
technical and scientific fields, so that if anything that they
should know about came along, then they would know about it.
They felt the best way to keep informed was to have people
actually doing research in these different fields; the

120

alternative might be having somebody sit in the library, but
they would be a year out of date at least. If you're in that
field, and you talk with the other leaders, you can really know
what's going on.

I was hired because John Bardeen wanted somebody to work on
superconductivity, but as I think I may have already said, by
the time I got there he was gone. But I wanted to try and work
on superconductivity. I didn't see anything else around that I
particularly wanted to do, so I did that.

Working up to the Laser

Riess: Okay, about this "not seeing anything else around that you
particularly wanted to do," you and Charlie had a close
relationship, a family relationship and everything, and the
maser was under development at Columbia.

Schawlow: Well, as I told you, I am one of the most anti-competitive

people you ever met. I wouldn't think of competing, especially
with Charlie, who was very good.

I did do a little work on nuclear quadropole resonance when
I first came there. I heard about it and it looked so
easyand it turned out to bethat I did some work on that,
wrote a couple of papers on it. [laughs] I remember I did some
work on resonances in the ultrahigh frequency region, that is
couple hundred megahertz. I had found one resonance in a
bromine compound and I couldn't find the other one. I thought
I knew where it should be because we knew something about where
the bromine resonances were in sodium bromate.

By scaling from chlorine, which is a somewhat similar atom,
I thought I had the higher frequency isotope, and I kept
looking for the lower frequency resonance--! think the one I
found was somewhere like 180 megahertzand I couldn't find it.
Then I thought, "Well maybe it's the other way around," it's up
around 215 or so. But there was a television station there. I
found that the television station was only off the air from
midnight to six a.m., or something like that. So one of the
very few times that I came in at night, I came in and looked
and found the resonance I was looking for.

The apparatus I used was extremely simple and primitive-
looking. I remember I had a visit from Professor Gutowsky from
the University of Illinois. He took a look at this and said,
"Well, I've never had much luck with simple apparatuses,"

121

something like that. Or "primitive," I forget what he called
it. Well, it was pretty crude, but I was just sort of
exploring.

I had some reason to do it because these were moderately
sharp resonances and they might perhaps have been used for
frequency standards. But I measured the temperature dependence
of themthey "re quite sensitive to temperature, and they
weren't really awfully sharp, so they were not suitable. I
mean, 1 did explore them enough to find that and also get a
little data of interest to the physical chemists although I
really didn't understand it very much. It gives some
information about chemical bonding, but not much.

Riess: You said that to have thought much more about the maser would
have been competitive?

Schawlow: Well, at that time it was only the ammonia maser, the other

kinds hadn't been invented yet. By the time they were, there
were a lot of people in the field, including a group at Bell
Labs. In fact, they came around and asked me if I'd like to
work on masers, maybe about 1956 or "57, and I said no. I just
really couldn't see getting into that.

Riess: But at the same time weren't you and Charlie talking about the
potential for an optical maser?

Schawlow: No, we didn't talk about that at all until the fall of '57--I
think it was October. By that time he was consulting at Bell
Labs and we had lunch together and decided to cooperate. I had
begun thinking about trying to find ways to make infrared
masers; I hadn't gotten very far but I was thinking about it.
Then Charlie came and said he'd been thinking about it too.

See, the original idea of the maser was to get wavelengths
shorter than you could produce by radio tubes, but it had not
succeeded in that. It had other uses: an atomic clock and
sensitive amplifier for radio astronomy and radar and so on.
The interesting question was: could you extend it farther?

Well, my thoughts were to just take the next small step, go
into the far infrared, closer to the microwaves. But Charlie
pointed out that in fact it might not be any harder to go to
the visible or near visible region. That appealed to me
because there was really at that time very little information
about spectra in the far infrared, and the spectra are the raw
materials that you have to use. So we agreed to think about
it.

We had to, first of all, see whether you could get enough
excited atoms at one time. A maser or laser requires that

122

you have more atoms in the excited state than in some lower
atomic state or molecular state, and this doesn't ordinarily
happen. In fact, in thermal equilibrium at any temperature
whatever, no matter how high, there are always more in the
lower states than the upper states.

But he [Townes] had shown in the ammonia case that he could
do it, he could find a way. Well, in the case of a microwave
maser, the relaxation is very slow: that means the molecules
when they are excited don't radiate very fast; they'll stay
excited so you can accumulate enough for the purpose. Whereas
in the optical region they usually emit their radiation in a
millionth of a second or less. But it turns out that that
doesn't matter too much. Still, we had to get some specific
examples and try and calculate how many that we might need.

I started to look into the alkali metals: sodium,
potassium, rubidium- -because they have the simplest spectra.
In a way, that may have been a mistakewell, those were the
things we could get information about, but some of the more
complicated ones are more useful.

Riess: Was this an issue of getting materials from Bell Labs?

Schawlow: No, no, this was purely theoretical. What we did was to go to
the library and search. Although the spectra were pretty well
known, widely published, what was not so widely available was
the transition probabilities, or lifetimes of excited states.
They're closely related because if the atom is going to be
stimulated, it needs to have a certain coupling to the
electromagnetic field. And that same coupling is what causes
the radiative decay. You can't think of the spontaneous
emission as really being stimulated emission, stimulated by the
vacuum fluctuations. In the microwave region, it would be the
thermal radiation around; in the optical region, it's the
fluctuations in the electromagnetic fields of the vacuum. It
has no average field, but it does fluctuate.

It turned out, as a matter of factCharlie had the
equation and I turned it this way and that to try to see what
it implied, the maser equation it turned out that it didn't
really matter what the lifetime was because if the lifetime was
short, you didn't need very many because they were more
strongly coupled to electromagnetic fields. If the lifetime
was long, you had to have more. So the number didn't matter.

What did matter was the efficiency, what fractions of these
atoms would be stimulated to emit in the particular decay
channel that you wanted, at the particular wavelength or
transition that you wanted. If they were all going to go off

123

at some other wavelength, then that made it inefficient. So
that was something that we realized, that it was more important
to have good quantum efficiency.

The second thing: we had to know the absorption strength to
know how much light we would need to excite the atoms. We
didn't think of anything at that time except exciting them by
light from another kind of a lamp. A method of optical pumping
was known in connection with Kastler's work using light to
excite atoms to an excited state from which they decay to a
particular chosen level of a ground electronic state. But we
were in thinking of optical pumping in a different sense, as
using light to get atoms into the upper state so we could get
the maser action. One of the advantages of the alkalis was
that you could get lamps of the same material and they would
have the right wavelength for pumping.

Now, of the alkalis, I concentrated on potassium, which was
wrong for some reasons. The reason I did it was a very foolish
one. I mentioned how hard it was to get equipment when I first
came, but the one thing I did get was a wavelength
spectrometer, which is a visible spectroscope: you look through
the thing in the visible range. I got that for measuring the
thickness of thin films. I had that around, but it only worked
in the visible region. Potassium had the interesting property
that the first and second absorption lines in the spectrum were
both in the visible, one in the deep red and one in the blue--
whereas all the others, at least one of the lines was out of
the visible spectrum, either in infrared or the ultraviolet.

The reason it turned out to be bad was that potassium is
very reactive chemically. After we'd finished our paper,
Charlie put two students and a visiting scientist on trying to
make a potassium laser, and they didn't have much luck because
the slightest trace of oxygen in the device would quench the
fluorescence. But we could work it out and that's what we used
in the publication. You could see that with reasonable lamps,
you could get enough excited atoms to get stimulated
emissionget enough gain so that with reasonable mirrors you
could get reflection.

It's funny, at first we thought of the thing really as like
a maser with a box resonator. It's curious that we had "L" was
the width of the box, and "D" was the length--! think that's
the way it was in the paper toowhereas obviously "L" is the
right thing to use for the length and "D" for the diameter.
But that was something we inherited from the maser. I forget
whether we turned that around before we finished the paper or
not. I don't think so.

124

As I say, I spent a lot of time looking in the Landolt-
Bornstein Tables for transition probabilities. These are
monumental tables published in Germany, many volumes. There
wasn't much information about transition strengths, but there
was enough for these simple atoms.

L J.W1. L.11COC OJ.Ui^XC at-UUiO.

for going through that. I know you've written papers
er this in a very clear way.

Riess: Thank you ior going i_nrougn mat. i
that go over this in a very clear way

Mode Selection

Riess: What I think is interesting at this point is to get an

understanding of why Bell Labs called Charlie back to consult,
what their motivation was. Did they think he would come back
and work on this with you? Was that the intention? And during
that time, where did you meet? Did you meet there, or was this
all happening on the phone? What were the circumstances.

Schawlow: They called him back because Nicholas Bloembergen had invented
the solid state maser, which was obviously a very sensitive
amplifier for microwaves, and was tunable. The first one was
built at Bell Labs. Bell Labs very quickly got a license, I
guess even before the patent was issued, and [H.E.D.] Scovil,
[G.] Feher, and [H.] Seidel built the first tunable, solid
state maser.

I think they wanted Charlie to help with the progress of
the maser program. They did not think at all about optical
masers or lasers. This was something just off the books. He
came to Bell Labs from time to time to see the maser people,
and we would talk in my lab .

Riess: How did the two of you work together?

Schawlow: He gave me, I think, some notes that he had made. He had

originally proposed thallium and I decided that wasn't going to
work because the upper state would empty faster than the lower
state so that you wouldn't be able to get an inversion. Well,
I'm not sure I was clever enough to find an alternative way to
use it, but he accepted my arguments at the time, so that's
when I switched to looking at the alkalis, potassium in
particular.

We would talk for maybe half an hour or so and I'd tell him
what I'd been doing. One illustration of that is that we did

125

discuss the question of mode selection. He had thought that
you'd use some sort of a box with reflecting walls that would
be much bigger than the wavelength. For the maser, you could
have a box that was comparable in size with the wavelengths so
that the wave would only fit in one way, and that would mean
that you would get one pure wave stimulated. On the other
hand, in the optical region, the wavelength is 30,000 times
shorter and if you could make a box that small, you wouldn't
have any room to put any atoms in it. (Actually, it's been
done since then.)

So we thought, from the beginning, of something of
convenient dimensionscentimeters or more. Martin Peter, a
Swiss scientist who had gotten a Ph.D. at MIT with Strandberg,
had worked some on mode selection there, and he kept urging me
that we had to find a way to select one particular mode of
oscillation. Well, Charlie felt that even though we couldn't
do that, that somehow a few modes would probably have higher
gain or lower losses than the others, and might stand out; it
might be jumping from one mode to another, but it would be
enough different from an ordinary lamp that you could see it.

Well, under Peter's urging I was thinking about it.
[laughs] My sister claims it was while I was shaving, but I
thought of using two small mirrors far apart. This is like the
Fabry-Perot interferometer that I'd used as a graduate student,
but not really like it, because those plates were big and close
together and these would be just two tiny little plates at the
end of a pencil-like column of active media. I thought, "Oh
boy, the wave has to go"--simplemindedly--"if the wave's going
to get from one mirror to the other it has to go straight along
the axis, otherwise it'll go off and be lost." That's why I
estimated that you could get the radiation down to an angle of
a few degrees. The wavelength would be selected by the atoms;
they would only support a small range of wavelength.

I told that to Charlie--! think the next day I happened to

see himand he said, "It's better than that, because the wave

is going to bounce back and forth many times, and therefore
we'll get really good selection."

Riess: So that was an exciting moment.

Schawlow: It was, yes. I think at that point we felt that we had it, and
the only thing left was to write it up. We could have tried to
build one, but I didn't have any equipment, and I had only the
one technician, and I didn't think of asking for help which
maybe I could have had, I don't know. But it just seemed
impossible to build one for me.

126
Riess: And Charlie couldn't have gotten Columbia organized?

Schawlow: He did, actually. Somewhere around February or March of '58 we
made the decision that we should write it up. But instead of
trying to build one--well, I think we both agreed it was
important to write it up first because of what had happened
with the maser. I think I've told you about that already, that
he had the maser idea, and in those days it was not considered
proper to write a proposal of what you were going to do but
rather to do it. That almost cost him a Nobel Prize, except by
accident it was published. So we decided to publish it rather
than try and build it.

Riess: The sense of excitement--! want to know what it was like.

Schawlow: It was exciting to have the ideas that fitted together--

couldn't be sure, though, that we hadn't overlooked something.
When we presented a draft of the paper for review, some of the
theorists including Clogston gave us a hard time because they'd
never heard of such a resonator. It was a very strange one
with open sides. They said, "How do you know what the modes
will be in that kind of a resonator?" Well, I didn't know.
All I had was this simple-minded view that if the wave was
going to go from here to there, it has to go straight back and
forth.

Charlie did put in a little stuff about how much
diffraction would spread it. In fact, diffraction is
really what makes it workthat is, the spreading of a wave
around an obstacle. You see, you start out with one atom, say,
and it emits some radiation, and it'll be a circular wave,
though, spreading out, and some of it travels along the
direction of the axis and gets reflected and stimulates other
atoms to go the same way. The light will spread out as it goes
back and forth until it fills the space within the mirrors.
This is by the process of diffraction.

[laughs] I gave a talk at a conference in 1961 in England,
an optics conference. Professor Hopkins there said, "I don't
understand how the wave fills the resonator." I tried to
explain but he said he still didn't understand! We didn't have
a rigorous theory for this kind of resonator. Not long after
that was developed by Gardner Fox, and Tingye Li. They did a
numerical calculation of the waves between two such resonant
mirrors in the resonator and came out with a pretty good
description of it.

It's interesting, several people said, "Why don't you use
spherical mirrors"--there is a spherical Fabry-Perot--"because
the losses would be less." Indeed, George Series suggested

127

that in 1959. But in fact, you depend on the losses. The
ratio of the losses for the different modes is the same, but
the absolute value of the losses is larger for the flat
mirrors. And if you're working with a solid material, you have
pretty large gain and you need fairly large mirror loss to
exceed the loss from scattering in the material. So the losses
at the mirrors have to be big enough so that only the highest
gain mode survives, whereas in a gas laser they do use
spherical, or sometime one flat and one spherical mirror, which
have lower losses, because they have very much lower gain.

Riess: You mean spherical or do you mean concave?

Schawlow: Concave, yes, parts of a spherical surface. One kind uses a
flat mirror and then the other end is a spherical, concave
mirror whose center of curvature is at the other mirror. Well,
people worked out the losses; in certain spacing between the
mirrors the losses are large.

By about 1963, that's after I left Bell Labs, I was
beginning to get annoyed by these people saying you needed to
have very low loss mirrors and to use concave mirrors for
everything. So I actually suggested that you might make
mirrors that are curved the other way, that are divergent, for
high gain materialsand indeed, people do that for high power
now. I didn't bother to patent it or anything, but I did
mention it and it's been developed; the theory and all that's
been worked out particularly by A. [Anthony] Siegman.

Riess: You were just saying it to make the point.

Schawlow: Yes.

Riess: Your sister said you got the idea shaving. Did you?

Schawlow: I suppose I must have told her that, but I don't remember. I
really don't remember it, any more than I remembered rooming
with Charlie in Washington!

About the Patent The Smell of Success

Riess: We've talked before about your not having filled many

notebooks, but you did write down your ideas in February 1958.

Schawlow: Unfortunately that was just before I had thought of the two
flat mirrors. I was thinking about it. I thought of things
where you might use diffraction gradings on the walls that

Riess:

Schawlow:

128

would reflect different wavelengths differently, at different
angles, which later have been used by other people to tune
lasers. But I didn't do anything more with it. I think I did
describe the potassium system.

I'm not sure exactly what was in those notes because I have
only one page of it which the Bell Labs people copied and sent
to me. But I don't have the rest of it.

You put these ideas downyou knew you had a big one here?

Well, yes, I thought it might be something good, that we were
kind of getting there. I think by that time I decided that the
potassium system could be made to work, so that I had something
to write about, and I did put down our thoughts on mode
selection.

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Then I had it witnessed by Sol Miller, who was one of
Charlie Townes" former students, who had a lab next door, I
think it was. They had a system at Bell Labs where they would
keep people separate departmentally, but they would mix them
geographically, deliberately, so you'd get to know people in
other areas of the company without having any responsibility to
work for them. So I told him about it, he read it, and
witnessed it. That was Friday. And then I was rather
horrified on Monday to learn that he had gone to IBM.

How extraordinary! And he didn't tell you.

He didn't tell me, no. I think it was that close, yes.
don't think it did any harm.

But I

You also say it seemed best to publish without waiting for
experimental verification. But you had to circulate the
manuscript for technical comments, and also to the patent
department.

Yes. And the patent department didn't want to do anything
about it. But Charlie sort of insisted. They said, "Well,
this is a maser, just a different wavelength," you know. They
didn't realize the importance. And I think really the patent
wasn't nearly as good as it could have been if they or we had
thought it was important.

I had never patented anything before, but Charlie had and
persuaded them to file for a patent. We helped them somewhat,
but we didn't put down all the ideas we considered obvious.

Something Charlie points out in his oral history is that when
he had been working at Columbia he was used to talking about

129

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:
Riess:

Schawlow:

Riess:

Schawlow:

Riess:

everything he was doing with everyone around him, but that when
he was working with you at Bell Labs he didn't talk openly
about what he was doing.

Well, I did. I pretty much talked with anybody that wanted to,
certainly anybody at Bell Labs. Ali Javan was recruited by
Bell Labs about that time. He had been a student with Charlie
and then a post-doc. He came out for an interview and I told
him about it, and he did come to Bell Labs, but he might not
have. I didn't really try to be confidential at all. I don't
remember whether I told anybody outside of Bell Labs. I wasn't

trying to be particularly confidential,
it was going to work or not.

I didn't know whether

Something else you said in a paper was, "Being at Bell Labs, I
had been pretty thoroughly indoctrinated to believe that
anything that you can do in a gas could be done in a solid, and
can be done better in a solid. Al Clogston, my boss at Bell"--
he was boss within that Stan Morgan structure?

No, he replaced Morgan when Morgan became head of the chemistry
department. Actually he wasn't the immediate one. Ken McKay
came first. I don't know when Morgan left. It must have been
after only a few years there, and then Ken McKay. He came in
and then Clogston. Clogston was very supportive.

You say he, "encouraged me to, if I wished, drop
superconductivity entirely and begin studies of possible
optical maser materials."

Yes.

Then you say parenthetically, "Though no one suggested putting
together a group to build an optical maser."

That's right.

"Anything like that I would have to do myself."

Yes. That's right. Well, I just didn't know how hard it was
going to be. I didn't realize how easy it would be. [laughs]
I was very close and I just didn't realize it.

This is really a Joe Six-Pack question for you: did you smell
success with this? "We can get this thing patented and we can
really make out like crazy?"

Schawlow: No. No, I thought it could be important if it worked. I

wasn't absolutely sure that we hadn't overlooked something.
We'd been as careful as we could, but 1 don't know, I'm timid I

130

guess. Of course, I didn't know what it was going to be like.
I thought it might just give microwatts of power at some near-
infrared wavelength or something like that. And that wouldn't
be terribly useful.

Looking at Materials Ruby

Schawlow: I think I did mention in my articles that I started to look at
materials. In fact, in the paper, I mention that some solid
state materials have an advantage because they have broad bands
to absorb the radiation and still emit it in narrow lines. I
thought you had to have narrow lines because our equation said
that the gain was inversely proportional to the line width, so
the wider the line, the less gain you'd get for a given number
of excited atoms. I really had a fixed idea that you had to
have narrow lines, which turned out to be wrong later in some
cases. But to get started, that's what we needed.

1 knew nothing about solid state spectra and I always like
a chance to learn something new, but the only one I knew about
at all was ruby, which is chromium in aluminum oxide. We knew
about it a little bit because ruby was by that time being used
for microwave masers and it was one of the best materials for
them. So you could find people that had drawers full of ruby
crystals. One thinks of ruby as a very expensive gem, but
artificial rubies are not expensive at all. They are made in
large quantities. They were used for watch bearings in large
numbers and I don't know what all else.

Riess: But they have the same properties?

Schawlow: Yes, in fact they are better than the natural ones for optical
things, because natural ones are never very large or pure or
unstrr ned. In fact, ruby always does have some strains in it,
it's h^rd to grow it without strains. But ruby does have a
broad absorption band in the middle of the visible so that a
broad band lamp could pump it, like a flashlamp, a photographic
flashlamp. It does have a sharp line in the red, or a pair of
sharp lines called the R-lines.

So I thought, well, I'll look into ruby and see what I can
learn about it, try and find out how the line width depends on
temperaturefor instance, would it get sharp at low
temperatures?

Riess: This was while you were still there at Bell Labs?

131

Schawlow: Yes, yes, we did a lot of work the last two years there. We
also looked at chromium in a couple of other materials:
magnesium oxide, which is a simple crystal, like rock salt
structure, but it couldn't be grown easilywell, it was grown
for other purposes in some electric furnace, I forget where,
not at Bell Labs. And also we looked at gallium oxide.
Gallium is related to aluminum in the periodic table. There's
aluminum, gallium, indium.

They had a marvelous crystal grower at Bell Labs, Joe
Remeika. (Oh, I was going to tell you a story about him.) He
grew some crystals of gallium oxide with various concentrations
of chromium in them. We knew that there were other lines in
the spectrum, and nobody had any idea what they were
fluorescent lines to the red of these strong R-lines. I
guessed that they might be from coupling of vibrations in the
crystal to the emitting atoms.

However, Remeika grew crystals of gallium oxide with
different chromium concentrations. George Devlin noticed that
the strength of these other lines relative to the R-line was
different in different crystals. In fact, the more the
concentration, the stronger these lines were. He pointed it
out to me and I immediately realized that the lines had to be
due to pairs of chromium ions that happened to lie close
together, because the higher the concentration, the greater the
chance of having pairs of ions. So we spent a good bit of
time, both there and again at Stanford, studying these pair
lines and trying to find out which pairsthe crystal is only
moderately complicated, but I think there are a number of
nearest neighbor pairs. There's a pair there right along the
symmetry axis, and various pairs at different angles that had
different distances.

In fact later at Stanford we put stresses on the crystal in
different directions to see which lines shifted most with a
particular direction. But before I leave Remeika, I must tell
you an amusing story. This was earlier. There was a time when
people thought that ferroelectric crystals would be useful for
computer memories. Now ferroelectric doesn't mean it has any
iron in it, but it has an electric susceptibility that
resembles the magnetic susceptibility of a ferromagnetic
material. However, people had trouble with these things not
being good insulators, they would act as semiconductors rather
than insulators and were too lossy because the currents would
flow through them. Remeika found that he could grow good
crystals if he did them in an iron pan, so they got a little
bit of iron in them which acted as acceptors to cancel out the
donors in the material. They called this Project Ironpan.
[laughs] They kept it secret for a while.

Riess:

132

Walter Mertz, who was another physicist in the group who
later went back to Switzerland and became head of the RCA lab
there, was working on these crystals. He gave a talk at a
meeting of the American Physical Society. [R.M.] Bozorth was
the chairman at this, but he didn't know about this particular
project, so after Hertz's talk he asked him innocently, "Can
you tell us what was the difference in these crystals that were
so much better than the ones people had?" And of course he
couldn't tell them, which was embarrassing. [chuckles]

When you left Bell Labs, were you able to bring George Devlin
to Stanford?

Schawlow: No, I offered him to come, but he didn't want to come. He went
instead to stay to work with another of Charlie Townes' former
students, Stan Geschwind. And he stayed with him for twenty or
twenty- five years. Then he retired early and took a job at the
NEC Laboratory in Princeton, so he had a good pension, and also
probably a good salary.

Riess: What is NEC?

Schawlow: NEC is Nippon Electric Corporation, universally known as NEC.
That laboratory is headed up by still another one of Charlie
Townes' students, Joe Giordmaine, who had been at Bell Labs
too.

Riess: Were you at Bell Labs long enough to get a pension?

Schawlow: No, not one cent. In those days it didn't vest at all. I was
there for ten years, but I would have had to stay until
retirement to get anything. I think they've changed that. It
did leave me a little annoyed but I knew that was the rule.

Where were we?
Riess: You were working on the ruby.

Schawlow: We found out that these other lines were caused by the

interaction of chromium ion pairs. And I realized that these
pairs would have several levels, not Just the one ground state,
but they would have several levels near the ground within a few
hundred reciprocal centimeters.

Schawlow: We found the same thing in ruby. The lines had been known in
ruby for fifty years, but nobody had any idea what they were
about and we were the first to discover that they were caused
by chromium ion pairs.

133

We also realized that the lower levels of these particular
pairs of atoms would be split by maybe several hundred wave
numbers. (A wave number is equivalent to roughly a degree
absolute.) So if we could cool it down to low temperatures we
could empty the upper ones among this group of lower ground
levels. Instead of having just one ground level, we'd have an
array of a few of them, and then we could cool it and get the
empty lower state.

I thought, "Boy, that's what we need." We may not be able
to put very many atoms in the excited state and if we have an
empty lower state, then we'll get gain immediately. I actually
tried that, very sloppily, with what I had around. I still had
an old Dewar from the superconductivity days.

Riess: An old what?

Schawlow: Dewar, D-E-W-A-R. That is a vacuum flask for getting low

temperatures by insulating liquid helium. I had a of dark ruby
polished; the ends were polished flat and parallel as near as I
could get. (I still have the order for that.) I cooled that
down in this thing. But then I didn't buy a big flashlamp,
which I should have but I didn't. I just had a stroboscope
sort of thing, I think a General Radio Strobotac, which is only
about twenty-five watt secondsnot a very powerful flash at
all. I tried that and nothing happened so I just put it aside.

Riess: This story is painful in many respects which are obvious to
you, too, that the materials that you keep--.

Schawlow: I was stupid.

Riess: No, no. No! It's almost like you were programmed from those
early days of Toronto not to expect to be able to get hold of
what you needed if you wanted it.

Schawlow: I think that's right, yes. I think that's right. I just sort
of learned to make do with what I have. I did not have an
aggressive training. I think other students who came in had
been in labs where they had money, particularly in the years
like the late fifties and sixties when the government was
putting a lot of money into research and people got anything
they wanted. Yes, I think that's true.

Riess: But then on the other hand maybe it's given rise to more
ingenious solutions.

Schawlow: Yes.

134

Well, but then I really put my foot in it. I gave a talk
at the first Quantum Electronics Conference which was held in
1959 after we'd published our first paper. I mentioned about
the ruby pairs and said that they would be good for an optical
maser, but that the R-line was not suitable for maser action
because it went to the ground state.

Well, [Ted] Maiman next year proved me wrong on that, and
one of the reasons I said that was partly because I didn't
think quantitatively, but there were no less than three
measurements of the quantum efficiency of atoms when they're
excited to the upper level of the R-line, and they all were
between one and three percent. I don't know how they were so
far wrong, but if it had been that low then it wouldn't have
worked. In fact, we did some experiments which really
indicated that it was much higher than that but we didn't make
a direct measurement.

The experiments we did were on radiation trapping in ruby.
That was really almost the most fun experiment I ever did. I
had known from work in Toronto--! 'd heard Crawford talk about
itthat if you have a lot of atoms, then when one emits
another one may absorb it, so the light has a hard time getting
out, and the apparent lifetime will be longer. I forget the
exact course of the thinking: I think that sapphire, which has
only a very tiny trace of chromium in it, did give a lifetime
of something like three milliseconds. The papers exist, we can
check those things. Whereas the ruby was considerably longer
than that, I think as much as twelve milliseconds or something
like that. So I thought maybe it might be trapping. With the
collaboration of Darwin Wood of the chemistry department- -he
had a diamond saw and cut us a thin slice of ruby, and we
measured the lifetime. It was somewhat shorter, but not as
short as the really dilute material.

So then he ground it up for usthis was all done in a day
or so and it got shorter still, but still not as short.
Finally we took some of this black stuff that's like
plasticine, it's called Apiezon Q, which is used for vacuum
work, and we embedded the grains in the surface of this black
stuff so that one grain could not see the other. And we
finally got the lifetime as short as you got for really dilute
material.

Now that should have shown us that the quantum efficiency
was pretty high, because these things were able to catch it and
re-emit it.

Riess: Why are you saying that was fun? What made it fun?

135

Schawlow: Oh, well we did it so quickly. You try one thing, you get some
results; you have an idea and try that, try the next one. It
was really fun, I really liked that. That's what I consider
fun, when you start getting some results and that suggests
something else, and you can try that out. Usually though you
have to do a lot of preparation to try another thing. In this
case we were able to do it right away. So, we did this work on
radiation trapping and that really did show the lifetime was
longer.

Ted Maiman's Work, and Publication

Schawlow: Maiman, I think, made his own measurements on the fluorescence
efficiency, did a quantitative job, and realized that he could
actually excite enough atoms to invert the population. And he
did so.

Riess: And he built the first one.

Schawlow: He built the first one that worked, though there are some funny
stories about that too.

Riess: Go ahead.

Schawlow: Well, there was a very sad story about this publication. He
had a paper in Physical Review Letters, published I think in
May of 1960, in which he did some excitation of ruby. What was
it he measured? I thought he was working on optical pumping of
the ground state of ruby and didn't pay much attention to it,
although it was sent to me for refereeing and I said it was
okay- -except I made him put in something what concentration of
ruby he was using, how much chromium.

But then in June or early July, he got his laser working,
and he sent another letter to Physical Review Letters and it
was rejected. Now Physical Review Letters had published an
editorial saying there 'd been too many maser papers and they
weren't going to print any more maser papers. And he, I guess,
called it an optical maser and they rejected it. He thought
they'd done it because they wouldn't take any more maser
papers.

In fact, a few years later I talked with Simon Pasternak,
who was one of the coeditors of Physical Review Letters, and he
told me that they hadn't bothered to referee it. They felt it
was a case of serial publication, whereas they wanted people to
finish a project and write up a full report rather than

Riess :

136

dribbling it out in little bits and pieces. Since he'd just
had a paper published on exciting ruby, they didn't bother to
have anybody referee it.

Well, Maiman didn't know. He thought it was because it was
masers and he didn't ask for another referee, which is the
normal thing. Instead, he submitted it to the Journal of
Applied Physics and they said they would publish it. But
Hughes was quite excited about it and they had a high-powered
publicity agent they hired for the thing, and this guy sent
around preprints of Maiman 's article for Journal of Applied
Physics to various trade journals. One of them, British
Communications and Electronics, published it, without
permission. They did it quite quickly, I think in August.

They'd had a press conference in July, that was when they
announced it. I had a preprint of it- -so did a number of other
people. This press conference got a lot of attention.
However, once this British Communications and Electronics had
published it, the Journal of Applied Physics said they couldn't
publish it because it had already been published. So then he
finally sent a slightly abridged version to Nature, and they
published it I think around September.

In the original article he said only that he used a crystal
of centimeter dimensions. And I think he made some remark that
because of the reflections from the side walls it wouldn't
produce a beam- -I don't know exactly. So we thought, well,
we'll get smart. At that point several people at Bell Labs
quickly got into the thing and set up big flashlamps.

Under you?

Schawlow: No.

Riess: But you were still associated with it?

Schawlow: Yes. They were friendly. There were two groups. One was with
Bob Collins, Robert J. Collins, and Don Nelson. They were in
the same building and we talked quite a lot. In fact I had
talked with Collins earlier about potassium lamps, how much
light you could expect, and that sort of thing. So they built
up a ruby laser.

Maybe I ought to go back a minute and put in something I
forgot about. In this first Quantum Electronics Conference
paper I wrote up that the structure of a solid state optical
maser would be especially simple: just a rod with the ends
polished flat and parallel and coated to reflect light, and the
sides left open to admit pumping radiation. Well, when I saw

137

the picture of Maiman in the newspaper with a little rod of
ruby, it was exactly what I had in mind.

Anyway, the people at Bell Labs thought they would check
the predicted properties. I couldn't resist joining in some of
that with Collins and Nelson. I had a good spectrograph so we
could measure the line width and found that it was sharper- -the
stimulated fluorescence was narrower, as predicted.

Riess: Say that again.

Schawlow: The emission bandwidth of light emitted by the laser was in a
narrower band than the spontaneous emission of the ruby by
itself. That is, at lower powers it would have would have
emitted over a certain broad wavelength, but the only part that
was stimulated would be at the center of the emission line
where the gain was highest. So we verified that.

I had a good oscilloscope. It's amusing. I think I told
you that after I'd been there about five or six years they
loosened the purse strings for apparatus. People could buy
almost anything they wanted. I didn't buy anything very
extravagant, but when we got into this laser materials I
decided to buy the best oscilloscope I could find on the
market, the most expensive one. This was a dual beam
oscilloscope from Tektronix, so it could display two traces at
the same time.

Well, one of the things we did was look at the time
development of the laser pulse. George Devlin asked, "Is there
any sign of hysteresis?" That is, a thing having friction
being slow to start up and slow to stop. We thought, let's
look at the details of this line. The dual beam oscilloscope
turned out to be exactly the right thing because we could
spread out one of the traces, so that the whole scan was only
about half a millisecond or so, which was the length of a laser
pulse. You could see there were spikes, that is, it was not
going all at once but in narrow spikes. So we were the ones to
discover that. It's particularly so for the ruby, not for all
other lasers.

Riess: So does this mean then that you put pen to paper?

Schawlow: Well, in a short time. But then this other group, Garrett and
KaiserGeoffrey Garrett and Wolfgang Raiserwas working in
the other building. They were somewhat more competitive. We
didn't know exactly what they were doing.

It was really bothering me. One night I couldn't sleep. 1
was wondering, now does this thing really produce a narrow

138

beam? We couldn't see it in our early ones because we had this
bright flashlamp which put a tremendous amount of light, lit up
the whole room- -we really hadn't boxed it in. The next morning
I came in and insisted that we've got to look to see if we have
a beam. What we did was just use a camera to photograph the
spot that it was producing, and indeed it was a narrow beam. 1
And I thought we should get a narrow beam because we had a rod
that--I think I had suggested we have it rough-ground on the
side so that you wouldn't get a lot of reflection from the
sides.

However, a few days later the group of Garrett and Kaiser,
who were working also with Walter Bondhe was basically a

Riess: [from several pages later in the interview] Just a footnote to
something you said before. I couldn't visualize how you could
only test the focus beam by actually taking a photograph of it.

Schawlow: Well, it was silly, we didn't really have to, but we had a

camera which I'd bought for work on superconductivity, looking
at the powder patterns, a Speed Graphic camera, and you could
put Polaroid film in it. The reason we needed the camera was
because the whole room lit up. As I say, we just hadn't boxed
in the flashlamp. You'd put this thing up close, and you'd put
a shield around so to shield the camera without shielding all
the rest of the room, and put it up close to the rod or maybe a
few inches away, and then see whether you got a spot or not.

One of the things we did find there is that emission was
occurring from many separate filaments in the rod. You know,
one of the reasons why I didn't know whether it was going to
work was that this ruby was really a very poor optical
material. It's a very wavy structure in the thing, almost like
Coke-bottle glass somebody said, so was it possible that the
wave could go from one mirror to the other without being
terribly distorted? Well, apparently what happened was that
there were a number of little small paths that the light could
go through from one mirror to the end of the other and get
reflected back. So the thing actually lased in a large number
of small filaments.

And you could see that by photographing the end of the rod.
The obvious way, and we didn't always do the obvious things,
would have been to just build a box around the whole thing.
Even a cardboard box would have done to cut out the stray
light, but we were in such a hurry to try everything that we
didn't stop to do that.

Riess:
Schawlow:

139

crystallographer, but he was polishing the crystals for them,
and in fact he found good ways of polishing ruby crystals, a
very wonderful person, he contributed a lot to the techniques
at Bell Labs. Anyway, it was Bond, Garrett, and Kaiser, though
Garrett and Raiser were doing the experiments. They had a rod
that was not ground on the sides, it was just polished, but
they boxed it in and they could see the spot on the ceiling.
It was a small spot. It turned out that polishing the sides
didn't matter.

By about that time Maiman had also discovered that his
thing was producing a beam. He didn't publish it right away,
but Mary Warga, who was the executive secretary of the Optical
Society of America, very much on the ball with the early laser
stuff, she got him to give an invited paper at the fall meeting
of the Optical Society. The deadline for abstracts was the end
of July and in that he said he had a beam, so he must have had
it by about then. But it wasn't in print until October [I960].

So we had these various properties and we finally agreed
that we would set a deadline and we would pool everything we
had and write a letter to Physical Review Letters as of a
certain date- -I think it was in September. We did an
experiment with Collins and Nelson to show that the beam was
coherent; we got diffraction from a single slit. We were going
to do a double slit, but we ran out of time. So we published
that. We were careful not to use the word maser in the
article, but it was published without any problem in the fall
of 1960.

You published with Bond, Garrett, and Kaiser?

And Collins and Nelson. They had a press conference about that
time, Bell Labs did. There was a good bit of jealousy there.
They didn't want me to come first in the program, they had me
come somewhere in the middle to explain how the thing worked.
But they didn't fool anybody, the newspapers knew who had
started all this, but the jealousy was there all right.

I had promised to give a talk at the Northeast Electronics
Conference, and I had to send around an abstract for clearance.
Garrett and Kaiser objected and said something about shouldn't
all the authors of this paper be included or something like
that. I was really very upset, and I complained to Clogston.
He said, "Leave this to me, I'll handle it." But I said, "If
necessary, I'll just talk about the things before our
experiments." Anyway, I felt that they were jealous. Also,
there was increased secrecy, people doing things and not
telling you.

140

One thing of course I noticed was that all of a sudden I
had more people talking to me than I had time to talk with,
whereas before on superconductivity I was really all alone and
nobody cared about what I was doing.

Riess: This business about hysteresisdid George Devlin get credit?

Schawlow: I'd have to look that up. I did put him on a number of papers.
I don't think so, no, because that was included in a paper
where they already had six authors. I hoped we thanked him,
but I'm not sure.

One other thing Devlin did. When I was looking at the
spectrum of ruby I was studying how the line was dependent on
temperature, and it didn't get nearly as narrow as you would
expect to have at low temperatures. You'd think it should be
very narrow because the lifetime was milliseconds so it should
be a line width of kilocycles. But it wasn't, it was much
wider than that. So I was looking at the thing with high
resolution and Devlin was helping make the scans.

He noticed a little bump on the side of the thing, and he

insisted that that's real.
you know. He said, "That's

I thought oh, it was just noise,
real." Of course, again I realized
immediately that could be an isotope effect because there are
several chromium isotopes. And indeed it was. Remeika made us
samples of the separated chromium isotopes. Devlin was
wonderful. He didn't really know the theory of the thing, but
he had open eyes and he'd see things.

Riess: To track some of these publication dates then--

Schawlow: Do you have my bibliography? If you don't, I should give you a
copy.

Riess: The article for Physical Review that you and Charlie did came
out in December of 1958.

Schawlow: That's right. It was published very quickly. We submitted it
in late July or early August of 1958.

Riess: When you publish are there letters in response or is that not
the kind of situation?

Schawlow: Not usually. People can complain if there are mistakes in it,
like you didn't give credit to somebody, something like that.
But there was no response after that. The attitude of most
people was they didn't think it would work and gave various
reasons for it. But a few people believed in it, started out

141

to try and make optical masers with various materials. And by
the end of 1960 there were I think five different lasers.

Riess: The Quantum Electronics conference [September 1959] must have
been an exciting event in and of itself.

Schawlow: Probably. Most of it was on microwave masers. I was so busy
and so slow that I didn't go the first two days of it. I just
stayed back at Bell Labs writing the paper because I didn't
have time to do it before then. So I only went to the last day
of the thing. And there weren't many people working on optical
masers yet, but they sure were after that.

Riess: Did Maiman pick up on it from being in the audience or from a
later publication?

Schawlow: He had been in the audience, but also there was a conference
that Peter Franken sponsored on optical pumping at Ann Arbor.
He called me up just a few days before the meeting and wanted
me to preside at a session and give a talk. Well, there was no
time to get official clearance for a talkthat was in '59 too,
I think Maiman was there. But I did tell a little bit about
these pair lines which were in the course of publication. I
did suggest just that they'd be suitable for various kinds of
masers without being specific.

Riess: I'll be interested in the bibliography.

Schawlow: If you want to take a moment's recess, I think I can start the
computer printing it out.

Pressure Results in Exhaustion

Riess: It's clear that 1960 was a big year in your life.

Schawlow: It really was. We had a lot of results. It's one of the

reasons why I didn't try to build a laser myself--! should have
--but I was finding so many interesting things in these
experiments.

Riess: You said something about thinking about the ruby lines and you
couldn't get to sleep.

Schawlow: No, the thing I couldn't get to sleep about was I wanted to
know whether the laser produced a beam or not .

142

Riess: Okay, right. But it made me wonder how good you are about
leaving it behind when you come home?

Schawlow: Pretty much in those days. I didn't really work at home very
much.

Riess: Did you go in on weekends?

Schawlow: No. Things have changed at Bell Labs. There wasn't much

pressure in those days. I think we felt that everybody was
more or less equal. We didn't know what people were making.
Later on they made a point of introducing what they called
"octiles," where they were dividing everybody into categories
and said they were going to adjust salaries accordingly. What
I heard from others who were at Bell Labs later was that then
the pressure sort of grew, and people were working night and
day there. It wasn't that way when I was there. They did work
hard during the day, but that was it.

You couldn't help thinking about things sometimes. The
particular time when I was sleepless was when the three of us--
Collins, Nelson, and myself--knew that there were a lot of
things to try out. They did bring their laser down to my lab
because I had the spectroscope and oscilloscope and so on. So
we'd argue about what to do next, and it was at that point that
I sort of felt that 1 just had to take over and check to see if
there was a beam or not. And there was.

Riess: Was Charlie still involved?
Schawlow: Not very much.

tf
Riess: Was he still consulting at Bell Labs?

Schawlow: Let me think. I'm trying to get the schedule of things. In
1959 he took a position in Washington with the Institute for
Defense Analyses [IDA]. After that, he couldn't consult.
Columbia later asked me to come as a visiting associate
professor during the academic year 1959-60 to help his students
where I could and to teach some classes.

Riess: Students who were working on maser experiments?
Schawlow: Yes, that's right.

Well, that was a horrible time for me. That was I guess in
the winter of 1960 before any lasers had operated. It was
horrible because I couldn't leave the stuff at Bell Labs.

143

Devlin was still working, but he did flounder when I wasn't
there. Things were not getting done. I would go in [to New
York City], I don't know, three or four times a week, and I
would come home every night and that was a long trip.

I got sick. I got cold after cold, ended up with a fever
around the end. I was supposed to give a talk in June, or
July, at a meeting, and I had to cancel at the last minute
because I had a fever of 103 or so. At this point the doctor
finally gave me an antibiotic that took care of it. It was
just sheer exhaustion, and I've learned since then that if I
get overtired, I get sick.

Riess: How did Aurelia respond to that?

Schawlow: She was very good, but it must have been very hard for her

because she had the three children by then. Of course, when I
was home I'd do what I could. We did a lot of things with the
family when I was home, and we were involved with the church,
the nice young people's group that we were in.

Riess: By "respond," I would expect a sort of outrage.

Schawlow: No, she didn't push me to do anything. Then I think when I

started getting offers in 1961--I was approached by a number of
different universities--.

Riess: Let's get back to the chronology. You had a Columbia spring
semester, and that ended when summer came along?

Schawlow: Yes.

Riess: And then summer and fall you were back in the groove at Bell?

Schawlow: Yes, I guess so. Now, what was I doing? Oh, I was still
working on some of these solid state materials.

We had a visitor from Japan, Satoru Sugano, a brilliant man
and a wonderful person. He had already published papers on the
theory of ruby before he came. I think he must have come in
'59. It was before we published our work on the pair spectrum.
So I think he probably was surprised when he saw that, but we
did work on stressing ions and crystals, and he did some
theoretical work on that. I was surprised when I went to an
American Physical Society meeting and found he had been
collaborating with two other people at Bell Labs too. He was
just very productive.

I just had a fax from him two days ago. He retiredthe
Japanese style is they retire at sixty and usually take another

144

job for five years as a dean or something like that at another
place. And he did that. But he retired the second time a year
or so ago. He's building a house in the mountains in central
Japan, some town whose name he gave but which means nothing to
me. But he also apparently inherited some money and is using
that to set up a foundation to put on conferences in the fields
he's been interested in.

Publishing with Bell Labs--The Clad Rod Laser

Riess:

Schawlow:

Riess:
Schawlow:

You've talked about publications. What kind of support did
Bell Labs give you? Did they do the typing?

Yes. They did do the typing. How did they do that? I forget
whether there was a departmental secretary that did it or not.
There must have been. They did have a typing pool, maybe
that's where it was done. I don't remember.

I was in a carpool around that time and there was a lady
there who worked in the editorial branch who was supposed to
straighten out the language of engineers in their reports. So
I asked her to try and see what she could do with one of mine.
She said I didn't need her help.

No, I would say not.
are clear.

I think your papers, the ones I've read,

Well, once I get the ideas clear,
That's the hard part.

it's not hard to say it.

Was there a "publish or perish" feeling at Bell Labs?

No, not really, although I felt that I obviously had to produce
something.

I think I was probably in danger of perishing before I got
into this [maser work]. I don't think that I was very highly
rated at Bell Labs at all. I think I mentioned that they made
me the department safety representative and also asked me to
supervise a technician who was running the helium liquefier
which turned out to be a terrible headache. I worked hard to
get him classified to a higher rating, which he really didn't
deserve, but I finally managed to pull it off. But he didn't
get enough of a raise, so he then filed a grievance with the
union I think.

Riess: Well, good that you got on to this.

145

Schawlow: Yes. It's good that I got onto the optical stuff. The laser
was obviously something important. They realized that right
away.

Riess: So the clad rod laser?

Schawlow: That was something we did probably in the time you're talking
about, probably the end of 1960.

Riess: What does that mean, clad rod?

Schawlow: A clad rod. It meant that the ruby rod was the core of a

larger rod whose outside was clear sapphire. Now I'd heard
that the Union Carbide people were making some of their
crystals in a doughnut form, or like this, [draws] a disk.
They would drop sapphire or ruby grains on the edge and melt
them with a torch. And as this thing rotated [demonstrating on
lid of a sugar bowl] it would grow radially like that.

So I realized that they could grow one that had ruby at the
core and then sapphire outside that. I also realized that if
you look at the way the light goes in there, it's bent towards
the axis; no matter what angle it comes in from the side it's
refracted, because there's a high refractive index in ruby. It
bends more towards the center, so that all the light over a big
angle would come through this central core. Thus you get more
efficient pumping and so get lower pumping power required.

Riess: So essentially it's a sapphire-clad ruby rod.

Schawlow: Yes, that's right. Ruby-clad with a sapphire outside. We got
a patent on that, I think. But they were hard to make and they
were more strained than the pure ruby rod because the sapphire
has a slightly different crystal structure spacing than the
ruby, so it didn't quite fit and that strained the material.

An interesting thing was pointed out by Joe Giordmaine--he
explained why it was the early ruby rods produced a good beam,
even though they could get reflection off the sides. The
reason was this business of the focusing of the light as it
came in, so that it was more intense at the center than at the
outside. So as you'd reach the threshold for laser oscillation
along the axis of the rod, and not at the outside, and it would
be absorbing at the outside. That's why light that went out to
the side and was reflected wouldn't get amplified much.

I think that may have been what inspired me to think that
the clad rod, that here was the ruby and it was being focused,
but some of it was being absorbed and therefore wasn't useful

146

in the outer regions. So the idea was to have the same
focusing effect without the absorption.

Riess: What were the virtues of the clad rod laser?

Schawlow: Lower pumping power. More ef f iciency--you collect the light
more efficiently. It was fun thinking about it. It was the
sort of thing, again, that people didn't believe at first.

Riess: You like that, don't you?

Schawlow: I do, yes. I think I've said before, if you have something

that some people can't believe and say it's wrong, and others
say it's obvious, then I feel I have something good.

Time to Leave Bell Labs

Riess: Fall of 1960. I wonder what was going on that convinced you
that it was time to leave?

Schawlow: I had a whole lot of different experiments going on that I was
trying to do, a whole lot of ideas. I just couldn't do all the
things I had in mind to do, so I felt it would be good to have
students to work with me. That was the main reason, I think,
intellectually. Also, I was getting annoyed at the jealousy
that was apparent among some of the people at Bell.

Riess: Did you approach Bell with what you wanted?

Schawlow: No.

Riess: You just knew that within the structure it wouldn't happen.

Schawlow: Yes. Charlie ran into that too earlier. They encouraged his
work on microwave spectroscopy, but they wouldn't give him
another person to work on it. So I just kind of assumed that
was all one could do.

Now Ali Javan, who had the proposal for the helium neon
[He-Ne laser], which was the first gas laser, did manage to get
two others to work with him on it. Two very good people. So
maybe some things could have been done, but I think that was
the main reason. And then the question of Artie came up too:
New Jersey was a terrible place for illness in those days.

Riess: I want Artie not to be just brought in sideways. Maybe the
next time we could start out by talking about that.

147

Schawlow: Yes. It was a consideration, and in fact one of the reasons
why I went to Stanford rather than somewhere else.

Riess: How did you go about making yourself known, that you were
available?

Schawlow: Didn't have to. People would call me. I didn't apply for
anything .

Riess: What were the most appealing choices? Did you go to meetings
and talk to people, or did you already know all the
universities?

Schawlow: Indiana University invited me and I went and talked with them.
It was attractive. Although it wasn't a great university, it
was a good place and I think it would've been good. Professor
Mitchell was the chairman, and he had worked earlier on
resonance radiation and co-authored a book on it back in the
thirties from which we got a lot of information.

The University of Toronto came after me. That was, of
course, attractive in some ways, but Aurelia didn't want to go
there. She'd been to Toronto several times, and people
there--. Well, she was a Southerner and Southerners, you know,
you go to New York or somewhere they kind of twit you about the
lynchings there and things back there. And you go to Toronto
and they sort of come at you about the things that the United
States government is doing that they don't like. So she felt
that she just wouldn't be comfortable there, although if I'd
really wanted to go, I think she would have gone anywhere I
wanted. Certainly she didn't like the idea of going as far as
California, but there were good reasons to go.

I did get approached by Johns Hopkins and also Columbia,
but I think that was after I'd accepted Stanford.

Riess: Would you have to have brought your own money?

Schawlow: No, I really didn't know what the things were going on there

[at Stanford], but I sort of assumed there would be money like
there was at Bell Labs and I went ahead and ordered stuff. And
in fact the Microwave Laboratory at Stanford was well-funded.
I knew I'd have to apply for some money of my own, but they set
me up and get me equipment for things, some fairly expensive
stuff.

Riess: Did you talk about money with the other places? Indiana?

Schawlow: No, I didn't discuss what money they could provide. I know I

was used to--working at Bell Labs, well, sort of "money comes."

148
Riess: And money was coming for science then?

Schawlow: Yes. Actually it was beginning to decline slightly.

Apparently in the late fifties it had really been awash with
money and you could just get anything for any purpose. By then
it was beginning to get a little tighter, but it wasn't bad. I
got support from NASA first.

Riess: What did it feel like to be out of Bell Labs?

Schawlow: Well, nervous. I managed to get a one year leave of absence in
case I wanted to come back, but I didn't really think I was
going to. But you know, there were things I'd worry about--
like I had to teach, and I didn't know whether I could do a
conscientious job of teaching and still have any time for
research. Well, I guess I feel I've never had enough time for
either of them. But I could do an adequate job, I think. But
I could have been a better teacher if I hadn't had other
distractions.

The most productive time for experimental physicists is
between ages thirty- five and forty, and those were good years
for me. I was thirty-five in 1956 and forty in 1961, full of
ideas and able to get a lot of them tried out, and some of them
were working and other people were working on things I ' d
started. Of course I was trying to follow everything that was
going on in connection with lasers, which has long since become
impossible. So it was an exciting time.

Certainly when I heard about the announcement of Maiman's
first laser, I was really excited because then I began to
realize how important it was, because he'd got just a short
pulse but peak power of kilowatts. And I'd been thinking of
milliwatts. So this was much bigger than I had thought of.

When this picture of Maiman appeared in the newspapers, he
was holding a flashlamp, a pretty big flashlamp- -obviously a
General Electric FT 524, because there weren't many flashlamps
on the market at that time. He didn't say what he used and he
didn't mention the rod, and the rod was obviously a few
centimeters long, maybe five centimeters and about five
millimeters in diameter, something like that. Just, as I say,
what I'd been thinking of.

But in fact, that wasn't what he used. He used a smaller
lamp and a short, stubby crystal. I think it was this focusing
effect that made his produce a beam. Well, the question of why
he showed a different one [in the picture], one of his
colleagues told me the reason was that when the photographer
came to take the picture all of the lamps he'd actually used

1A9

were broken. [laughs] He himself has testified, I think in a
patent suit, that the photographer thought this was better
looking, but I don't know.

Riess: What was the patent suit?

Schawlow: I don't know. He did get a narrow patent on ruby lasers, but
the basic patent was ours, which was issued ridiculously early
in 1960, March of 1960 and of course expired in '77.

Riess: You had no control over that.
Schawlow: No.

We saw that picture and we recognized what it was, so we
bought some FT 524 lamps. The advantage of that was that I was
able to put a small vacuum jacket inside a glass finger, a
Dewar vacuum flask, so I could cool my dark ruby rod to low
temperatures and still get a powerful blast from it. That was
one thing that made it easy both to check that the lines got
sharper as you cooled the crystaleven the laser lines did--
and you could run the dark ruby pair line laser at liquid
nitrogen even.

Riess: We are looking at this picture from the IEEE article, July
1976.

Schawlow: Well, that one we usedit's not easy to see in this copy, but
we used a straight flash lamp and a reflector, an elliptic
cylinder reflector. But in our earliest experiments we used
the same sort of a Dewar that you see there, with a fairly
narrow finger but it had to be big enough to contain a vacuum
jacket. And we just put it down inside the flashlamp.

Riess: This is the drawing of the Dewar.

Schawlow: Yes. It shows it inside the cylindrical metal housing. I
think they cropped that a little bit so that you can't see
where the flashlamp is in the drawing, but the flashlamp would
be off to one side in the cylinder. There's the cylinder- -the
lamp would be over here somewhere and the light would be
reflected from the inside of that cylindrical mirror.

Riess: You do realize how simple this whole thing looks?

Schawlow: That's the way I am. If I had known it was that easy--. I
just couldn't think that anything that simple would work.

Riess: Isn't it extraordinary? I don't know whether this is like a
general principle of physics

150

Schawlow:

No, it's just the way I work,
complicated things.

I just don't have the mind to do

Riess:
Schawlow:

Riess:

Schawlow:
Riess:
Schawlow:
Riess:

Back to the first laser: now, a laser doesn't work until
you get above the threshold where you have enough gain from
excited atoms to overcome losses. Well, we had a very poor
ruby rod, and we had a power supply, and a big lamp that was
rated at 4,000 watt-seconds--that was the most you were
supposed to put in it--or 4,000 joules. But it didn't lase at
that. So I thought, "Well, what have we got to lose"--we
turned up the power and at 4200 joules it started to lase.
That same thing happened again once with one of my graduate
students, but that's later.

What do you learn from that?

You learn that there's a threshold and you have to get over
that threshold. It doesn't come up gradually. Well, there is
a buildup close to it, but it's a sudden thing. If you're
below the threshold, it isn't lasing; if you're above it, it

is.

A couple of stories you have told of going from doing things
the way you're supposed to, slowly and meticulously, to
blasting off, like when you were trying to--

Get those mirrors.

Yes, right.

Sometimes you have to be rough.

Ah! That's what I wanteda quotable end line: "Sometimes you
have to be rough."

National Inventors Hall of Fame, 1996
[Interview 5: October 30, 1996] II

Schawlow: [Talking about recent trip to Akron, Ohio, to be inducted into
the National Inventors Hall of Fame] By Thursday morning I had
bad chest pains, and that turned out to be pleurisy. I had to
sit up all that night because I couldn't find any position

151

where I could lie down. But then, as you can see in that
newspaper story, Dr. Forrest Bird treated me. 1

Riess: And who is he?

Schawlow: He's a member of the National Inventors Hall of Fame for

inventing various respirators. He had one shipped in and he
gave me a treatment and managed to get my lungs straightened
out. Apparently pleurisy only lasts a few days anyway, but he
got me breathing again pretty quickly.

[indicating the respirator] The thing is worth $3600. Dr.
Bird gave it to me, and that was because he is very grateful
for inventing the laser, because his wife just had an operation
for endometriosis with a laser. It's a pulsed respirator; it
puts out pulses of air up to five times a second and about
forty pounds per square inch. This is supposed to loosen up
stuff in your lungs and so on.

Riess: Quite a story, and quite a coincidence.

Now, what is this videotape that you've given to me?

Schawlow: That's quite a story too. Back in 1965 or 1966--the California
Academy of Sciences had been sponsoring a program called
"Science In Action" on educational tv, and this was near the
end of their run. They had an independent producer, and they
decided that they would do one on "the scientist," and they
somehow picked me as the scientist. They came down to my lab
and to my house, filmed me with my daughters. In that I talk a
little about how I felt about physics and things that you are
going to discuss today.

One of my former post-docs called and urgently wanted a
copy of that film. I could not find that videotape, and I'd
sent the film to Cleveland to use in the material for the
National Inventors Hall of Fame induction ceremony, and it
hadn't come back. So the day before yesterday I called them in
Cleveland. They said, "Oh, we sent that ten days ago, on
October 10." They sent it to the university. They checked and
found who had signed for it. Well, I asked the secretary. She
hadn't seen it. Turned out it was down in the mail room, they
had just left the box down there.

I got it the day before yesterday and yesterday I made a
copy and sent it to him. And I thought, well, maybe you would

'See Akron Beacon Journal, September 23, 1996.

152

be interested in that too. It's all about me and I do talk
about how I felt about things in physics.

Riess: You were the representative scientist.

Schawlow: Yes, just the only one they did. Instead of talking about some
particular discovery, they just talk about one scientist and
see what he does, see what he's like, that sort of thing, which
is a wonderful thing to have.

The people in Cleveland had made a good VHS copy from the
film, much better than I've been able to get made, so I made a
duplicate of the thing.

Riess: Thank you. Is that something you're able to do with your
equipment here, you can make duplicates?

Schawlow: Yes, well, I have two recorders so I can just take one from the
other room and hook it up here.

Riess: When you were in the hospital and surrounded by all the

electronic monitors and gadgets, did you have some curiosity
all that?

Schawlow: I was pretty sick. Well, I admired some of the gadgets but I

didn't really get into how they worked or anything like that in
detail.

Laser Action in Ruby- -Physical Review Letters, Feb. 1. 1961

Riess: Last time we had gotten to the point of your coming to

Stanford, but I realize you haven't told about your 1961
publication on laser action in ruby. That's the article that
was published at the same time as an article by [I.] Wieder and
[L.R.] Sarles.

Schawlow: Okay. I had been rather simplistic in my approach to things.
I had not really done any quantitative calculations, I just
sort of went by instinct. I used Charlie's maser equation as a
guide, but still--! saw that to get gain you had to have more
atoms in the excited state than in the lower state.

One substance that kind of fascinated me was ruby. I
didn't know anything about solids but I had a feeling that
well, it was sort of the Bell Labs culture, that anything you
can do in a gas you can do better in a solid. Ruby was a
crystal. There were samples around because they were using it

153

for microwave masers, and so I thought I'd take a look at the
spectrum of ruby.

Trouble was that the atoms are all in the ground state when
you startand although there's a good broad band that you can
pump into with the green region, and then the ions all populate
a level that fluoresces to the ground state and produce a red
line actually, there are two very close together. But the
trouble is that the atoms there are all in the ground state and
you'd have to excite more than half of them before you'd get
any gain. That didn't seem to me a practical sort of thing.

But as we studied the spectrum of ruby we noticed that
there were a lot of other lines there that were not accounted
for by the theory. Fortunately we found out that they were due
to pairs of chromium ions, because their proportion relative to
the single ion lines got stronger as you made it more
concentrated. George Devlin noticed that, actually in some
crystals of gallium oxide with chromium, which is closely
related to the aluminum oxide with chromium which is ruby.

So we saw these lines were due to pairs and they were split
by fairly large amounts by the exchange interaction between
these chromium ion pairs which, in concentrated chromium oxide
where it's all chromium and no aluminum, makes it anti-
ferromagnetic. That is, the spins of adjacent neighbors are
paired anti-parallel. Well, this meant that here was a system
that did have lines that were spread out over a substantial
regionand that meant that the energy levels were also split
by several hundred wave numbers, which is equivalent to several
hundred degrees temperature.

So it occurred to me that by cooling that stuff to a low
temperature--! didn't know how low you'd have to gothen you
could empty some of these lower levels, and then you would have
a much lower threshold. And all you had to do was get some
atoms excited and you'd get gain. How much gain you'd need was
hard to predict because the optical quality of these rubies is
very poor. Just like, somebody said, Coke-bottle glassthey
don't put Coke in bottles any more, I don't think, but anyway,
it was not optical glass.

I talked about that at the first quantum electronics
conference. We published the results. I foolishly said that
the R-line, which is the main line in rubies, was not suitable
for optical maser action because you have to empty the ground
state, but these ones would work.

Well, I tried it very crudely. I got a rod polished and
silvered, but I only had a twenty-five joule flashlamp.

ISA

Actually it was a Strobotac for measuring rotational speeds,
for motors or something like that. And that wasn't nearly
enough, and nothing happened, so I just put it aside, which was
foolish because Maiman then came along and showed that he could
get more than half of the atoms excited and get laser action in
ruby. That was the first laser. Then I helped Bob Collins and
Don Nelson get their first ruby laser working: they copied more
or less after what Maiman had published. We got that going
around the beginning of July or so of 1960. We then set out to
measure some of its properties, showing directionality and so
on. We prepared our work, and that of Bond, Garrett, and
Kaiser for a joint publication. We didn't use the word maser
because we thought that Physical Review Letters had a ban on
more maser articles, which they really weren't applying to
optical masers.

Then I remember asking the boss, "Should I try the dark
ruby?" He said, "You owe it to yourself." That was Al
Clogston. I got a big flash lamp and the same ruby rod. In
the article about it I thanked Walter Bond for polishing the
ends. It really was just one end that had cracked, the other
end was still the original. And it did work. I got it working
in November of 1960. In planning to publish these results I
decided, "Well, if Physical Review Letters doesn't want
articles on optical masers, I'm just going to send it to
Physical Review." That is not as prestigious, but it's a very
respectable journal.

Our paper arrived on a day that they had a big snow storm,
and a paper by [Irwin] Wieder and [Lynn R.) Sarles's also
arrived on the same day. They reported that they had observed
stimulated emission in dark ruby. I don't think they quite
understood what the difference between stimulated emission and
an optical maser was--I mean with the mirrors being essential.
The editors felt that they had to treat them in the same way,
and so our paper ended up in Physical Review Letters which we
hadn't requested.

Riess: What do you think the politics behind all that was?

Schawlow: Politics? The editors are great people. Sam Goudsmit was a

great scientist, and should have had a Nobel Prize. And Simon
Pasternak was the associate editor. These are great physicists
and they knew what they were doing, though they did make a
mistake on Maiman 's original paper. By that time they realized
they had made that mistake and didn't want to make another. So
ours appeared in Physical Review Letters at the same time as
Wieder and Sarles's paper.

155

Riess: I guess I shouldn't have said politics. When I see the

attention given to timing on all this I think, "Well, how is

this important? This seems petty, this concern." And. yet it's
not at all, is it?

Schawlow: No, science is cumulative. It puts another building block,
another brick, in the wall, so it's hard to tell. I think a
lot of the stuff that gets into Physical Review Letters is not
all that important, but they try to give things of general
interest. It keeps getting fatter and fatter. Now it comes
out every week.

Riess: But that requires that you read so much more, it seems like
there's not that much gain.

Schawlow: Well, there of course are huge numbers of papers published in a
lot of journals. But which one do people actually look at? I
think Physical Review Letters is one that a lot of people do
look at, even if they don't ever look at anything else.

Riess: Were Sam Goudsmit and Si Pasternak doing science as well as
editing?

Schawlow: I think by that time Goudsmit was semi-retired. I heard him
talk about it. He got famous back in 1924. He and Uhlenbeck
realized that the fine structure in atomic spectra could be
accounted for if you assumed that the electron had a spin.
Well, the concept of electron spin has been extremely important
ever since then.

This was a theoretical paper, but Sam--he really was an
experimentalist at heart and he somehow got labelled as a
theorist. He was at University of Michigan before the war and
after the war he went to Brookhaven National Laboratory. He
wanted to do experiments there, but they didn't want him to.
He did one. He built a new kind of mass spectrograph, I think
it was. But then they needed an editor for Physical Review and
Physical Review Letters, and he took the job which is certainly
a great service to the physics community.

It grew very rapidly. In fact when I first joined the
American Physical Society and for quite a few years afterwards,
there was just a letters section in Physical Review; and then
later they decided to publish Physical Review Letters as a
separate journal. Now the Physical Review has grown so huge
that hardly any individuals subscribe to it anymore. Libraries
have to. The cost is very high, hundreds and hundreds of
dollars.

156

I used to subscribe to it, kept it up as long as I could,
but it just got to be such a monstrous thing that I couldn't be
bothered with it. So I gradually cut down to two sections,
then one section, finally gave it up entirely. So anything
published in Physical Review I just don't see unless somebody
tells me about it.

Riess: And the sections are very specific?

Schawlow: There are five sections. There's one, I think it's atomic

physicsatomic, molecular, and general physics. I forget what
the others are: solid state, condensed matter, and nuclear.
Particle physics. I think there's a theoretical one too.

Riess: In editing the letters, is there a lot of back and forth with
the authors to be really clear about what they're writing?

Schawlow: Sometimes. Or sometimes they reject them. Sometimes the

authors fight back and manage to persuade the editors to print
their stuff after all. I know at least one case where the
paper was rejected by several people, including me, as being
not important enough to put in Physical Review Letters. But
the author was a very determined guy and he got it in.

Inventing Stuff

Riess: Well, that all may be a footnote but it's interesting because

publication and patent are both much more important than I ever
would have thought in science.

Schawlow: I have little use for patents because I had nothing much but
trouble from them. Of course I didn't get any money from the
laser patent. Bell Labs had given me a dollar for all patent
rights when I joined the company. But they did support me for
seven years before I filed any patent applications.

However, just recently I was inducted into this National
Inventors Hall of Fame, which is strictly based on patents. If
I hadn't had that patent, I wouldn't have that. And now, in
fact on Friday I have to go to San Jose to get the Ronald H.
Brown American Innovator Award which comes from the Patent
Office department of the Department of Commerce. This is a new
award that they started last year. Again, just because I had
that patent.

Riess: And you're the first recipient.

157

Schawlow: No, this is the second year. They are giving out seven this
year. It was given in Washington on the fifteenth, but I was
far too sick to go then. But the Commissioner of Patents, who
is a Deputy Secretary of Commerce, or Assistant Secretary I
guess, is giving a talk to the Patent Law Association in San
Jose on Friday and asked me to go there and they'll present
this thing to me.

Riess: Is Charles Townes a member of the National Inventors Hall of
Fame?

Schawlow: Oh yes. He was in years and years ago.

Riess: But aren't you identified as an inventor more than he is?

Schawlow: No, oh heavens no. He invented the maser and co-invented the
laser.

Riess: You have such an inventive turn of mind.

Schawlow: Certainly not more than Charlie, who is really a very great

scientist. But as I told the people in Akron, we experimental
physicists are always inventing stuff. We have to invent the
apparatus that will do the measurements we want to do, but
often there are things that are not worth patenting. I gave an
example, that in 1975 Ted Hansch and I published an article
showing that it would be possible to cool atoms down to very,
very low temperature free atomsby using laser light.

Well, we didn't do it at the time because we were
interested in hydrogen and there still isn't a suitable laser
for cooling it. I didn't even think to mention it in my Nobel
lecture. But in the eighties a number of people, including
particularly Steve Chu who's now with us at Stanford, but was
then at Bell Labs, showed that this would work and you could
get down to a fraction of a degree absolute. Then things were
fortunate. It turns out there are other mechanisms that we
hadn't thought of that make it even better than we thought.
And now they get down to micro Kelvins .

Since then it's become possible to use these very slow cold
atoms --they 're still free, but they're not moving very fast
they can measure the acceleration of gravity more precisely
than any other way, and that might be useful for prospecting.
It's still too big an apparatus to take out in the field.

Also, they can make an atomic gyroscope, which is probably
better than any other. So these are inventions that may be
worth patenting, though they're probably twenty years away from
being useful. We saw that it was so far away from being useful

158

for anything that there was no point in applying for a patent.
If we had it would have expired by now. But it was an
invention.

Riess: Yes. In order to apply for a patent you have to publish.

Schawlow: You don't have to publish it in a paper, but you have to have--
in fact, one of the things I don't like about patents is that
it's quite secret until the patent is issued, but you have to
give them a description that will convince them that it will
work, convince the patent examiner.

Ours was what they call a constructive reduction to
practice: that is, we described in detail how you would do it,
and so they issued the patent. More normally, they would like
to have a working model that shows that the principles of the
invention actually work.

Science Writers, Informing the Public

Riess: Interesting. In the sequence of things, there was a story of
you being asked to talk to the New York Times. You were being
asked for comment about Mirek Stevenson.

Schawlow: Oh yes. Stevenson had called me up the night before.

Stevenson was a student of Townes's and had gone to work at
IBM. It's quite an interesting story--! don't know whether I
wrote that up before. He was very much interested in business;
even as a graduate student he was making a lot of money in the
stock market. He later started an investment fund. I don't
know whether that's still going or not. At the time he had
taken this job with IBM and was working with Peter Sorokin, who
was a very brilliant experimental physicist and was a student
of Bloembergen's at Harvard.

I guess they heard--! 'm not sure if it was before Maiman
did his stuff or after. I think it's probably before Maiman
published his attainment of laser action. But Stevenson felt
they should do this in a businesslike way and buy everything
possible, don't take time to build it yourself. So he searched
and found the biggest flash lamp on the market and he also
found that they could buy the crystals that they wanted from a
crystal growing company. So they quickly got laser action in
divalent samarium and trivalent uranium.

I think it was Stevenson, one of them called me up the
night before it was officially announced. And I did find out

159

that it was trivalent uranium and divalent samarium. So when
the reporter called and asked me what I thought of, I said that
it was good stuff and told him what it was so they got the
story straight.

Riess: That must be a challenge, the public need to know, and dealing
with science writers and how to get things clear with them.
Has science writing improved over the years?

Schawlow: Well, there have always been some good ones. I think Lawrence
of the New York Times was very good, very careful. The science
writers were not bad. I think it's the regular reporters that
have to deal with a story that really get things garbled
sometimes. Even that has improved, I think. But I sort of
came to the conclusion that whenever I saw some story in the
newspaper about which I knew the facts, there was always
something wrong with it.

I really have to admire how science writers can jump from
physics to biology to astronomy and everything. Of course,
they tend to always want to fit it into a pattern. With lasers
it's either a death ray or a cure for cancer or both. That's
indeed the way it turned out, no matter what you told them,
pretty much.

Riess: You mean it's sort of the human interest.

Schawlow: Well, yes, that's what they want. And these were old ideas.

Of course, the death ray idea is much older than actual lasers.
Buck Rogers in the 1930s comics strips and E.G. Wells' War of
the Worlds--the martians had a sword of heat. Even back to
Archimedes supposedly burning the sails of enemy ships with
reflected sunlight. All these things. So this is an old idea.
And as soon there were any lasers, that's what they jumped on,
although the lasers that we had then were very primitive.

I remember calculating that if you could deliver one joule,
that's one watt second of energy, once a second, you could
completely vaporize a two hundred pound manbut he'd have to
stand there for two years.

Riess: Now that's an image! [chuckles]

Schawlow: I didn't think much of them as weapons, and in fact they're
still not really usable as weapons. They've got some giant
lasers that will fry things, but what they really want to do is
melt missiles at five thousand miles away, and that takes an

160

awful lot of power. It could be countered by putting a little
more shielding or more decoys.

Riess: When the newspaper calls, do you view it as an opportunity to
clarify things or do you greet it with dread?

Schawlow: I don't greet it with dread. I try to give them the story as I
see it, and I don't worry too much about how it comes out.

Post-Laser Atmosphere at Bell Labs

Riess:

Schawlow:

Another event. What you refer to as "the first public
demonstration of an operating laser" was at the Nerem
electronics meeting. 1

The Nerem meeting occurred in the fall of 1960.
we had a laser, a big clumsy thing.

By that time

As soon as lasers came on the scene, the atmosphere changed
at Bell Labs. First of all, there were a lot of people who
wanted to talk to me whereas before in superconductivity I was
pretty much all alone. But also there was some jealousy and
secrecy. People weren't telling things that they were doing,
even within the laboratory.

I had been asked months before to give this talk at the
Nerem meeting and I had agreed. But I had to circulate an
abstract for approval. One of the other people at Bell Labs
that had been involved in that combined paper about the
properties of lasers said that all the authors should be
consulted on this thing. Well, I got rather angry. This was
something I had done myself and I could talk about stuff that
they had published and give them some credit, but still the
original thing was mine.

I really was quite angry and I complained to Clogston. He
said, "Let me take care of this." I heard no more about it.

They'd had a press conference from Bell Labs before that,
and again I had this feeling of jealousy. In fact, they
arranged it so that I wasn't the first speaker. There were all
six authors of that paper on the properties of lasers and I
think they put me in third or fourth place there. I was

1 p. 143 "From Maser to Laser," Arthur L. Schawlow, in Impact of Basic
Research on Technology, Plenum Press, 1973.

161

supposed to explain the principles of the thing and they tried
to deemphasize me. Well, the newspaper wasn't fooled,
[chuckle] But that's why I really began to think of leaving
Bell Labs.

Riess: Was Bell Labs trying to recast the invention in terms of being
a kind of communications breakthrough?

Schawlow: They did want to emphasize that all right. And these people,
they'd all done something. But they wanted to feel their part
was just as important as anybody else'swhich it wasn't. Mine
had come first, and the whole thing wouldn't have been thought
of if we hadn't done what we did.

Riess: It's hard, as I sit here, to imagine you getting very angry.

Schawlow: [laughs] I don't very often. But that really annoyed me. I
said, "Well, if they want, I'll just talk about the theory and
not about any of these results."

Riess: In fact, you did have contacts with the newspapers and you

could have gone public and really embarrassed them, I suppose.

Schawlow: Well, I'm not that kind.

Gordon Gould, and the Competitive Drive

Schawlow: I always feel that it's better not to attack others but just to
say my piece. Now of course, one thing that I really hate to
mention is Gordon Gould. He's been a real thorn in the flesh.
He got elected to this Inventors Hall of Fame years ago, but
his forte was patents. Patent lawyers control this thing
pretty much.

He was a graduate student of Kusch's. He'd never finished
his Ph.D. He was older than I am, a year older. But somehow
he got wind of what we were doing and he started writing stuff
in his notebook. Oh, some months after our patent was filed,
he filed a patent applicationnearly a year after. There was
interference, and fortunately both the patent office and later
the courts decided that he hadn't shown conception of the ideas
in sufficient detail to be acceptable. Also he hadn't shown
diligence in reduction to practice. But his lawyers filed

Riess: Diligence in reduction
Schawlow: --to practice, yes.

162
Riess: What is that expression?

Schawlow: Well, it means either writing a detailed description that a

person "skilled in the art" could duplicate, or actually making
one.

Riess:

He went to work for TRG, and I think his agreement was that
anything he had done before then was his, but anything after
that was theirs. But he kept on adding to his notes for his
own personal patent application. To give you an idea of how
dirty they were, two things: I can't say how much was his and
how much was his lawyers and backers , but the company that was
sponsoring his patent stuff, after TRG, a company called Refac,
I think, and then later Patlex, they got into trouble because
they were doing insider trading when they heard that his patent
was going to be issued. They bought some of their own stock.

But worse than that, the patent office decided that he
hadn't shown conception of the idea and also hadn't shown
diligence in reducing to practice. Then they took it to
courtat that time it was being sponsored by Control Data,
which had bought TRG, and they had plenty of money for good
lawyers. But the court--! think there were three judges, and
they ruled unanimously that he had not shown conception of the
idea. Two of the judges ruled that he hadn't shown diligence
in reducing to practice. The other one said, "Well, since he
hadn't shown the conception, we don't need to rule on that."

Then they put out press releases that this had only been
rejected on the narrow grounds of insufficient diligence in
reducing to practice, which was just a plain lie.

Later, to give you an idea of what they did that was really
rotten, they went after a lot of little companies. They were
very smart at managing. They bought off Bell Labs and General
Motors, I think, who could have put up a real fight, by giving
them a cheap license.

You mean Control Data did?

Schawlow: No, that was later. It was Patlex or Refac. It was after the
Control Data time. I think Control Data just gave up on it
after that point.

They went after a little company in the San Francisco area
and this guy was too poor to hire a good lawyers to defend it.
But in court, the lawyer for Gould's side got up and said, "You
wonder why this great inventor hasn't received the recognition
he deserves. Well, his professor," meaning Charles Townes,
"had witnessed his notebook of an idea for optically pumped
maser and then later put it into his own papers."

Riess:

Schawlow:

Riess :

Schawlow:

163

This was really a disgraceful lie. Because, first of all,
Charlie Townes had this particularit was just for an
optically pumped maser, not a microwave maser. And Charlie had
this idea in his notebook several months before that. And this
had come out in earlier patent litigation, so it was public
record and yet they lied and made it sound as if he had stolen
some of Gould's ideas. And you know, Charlie is the most

honorable man you ever met.
playing that they did.

But that's the kind of dirty

Then they scrambled around and looked at things that maybe
we hadn't quite specifically mentionedwe didn't really try to
think of things around. They threw out his patent application,
but the court forced them to reinstate it. They had accused
him of lack of candor, meaning he'd said different things in
different cases.

He got a patent finally on maser amplifiers, said that we
had only shown an oscillator. Well, you can't make an
oscillator without having an amplifier. An amplifier provides
the gain and then you have some kind of feedback. So we
certainly had amplifiers. But then they tried to collect
royalties on any laser. They said, "Well, it has an amplifier
and we have a patent on the amplifier."

It an extraordinary story because it's so singular,
hear stories of this kind of greed and duplicity.

You don't

Riess:

Well, this outfit had apparently done something similar in
ultrasonic testing.

Anyway, he did get a patent on gas lasers and I don't know
just what he had that based on. They collected a lot of
royalties on that.

But do you put it to the company, Pat lex, or is it Gould's
hysterical approach?

Hysterical is not the word. But yes, I think he had a lot to
do with it. Although the lawyers, at one point, boasted that
Gould had invented the laser but they had invented the patent.
And his patents were issued many years after. Of course, that
was good because by that time there was a lot of business to
collect from. But he just maneuvered and made it not
worthwhile for anybody to fight it even though it really could
have been fought.

No, hysterical is not the word.

Schawlow: Devious.

164
Riess: Yes. Science is relatively free of that sort of thing.

Schawlow: This wasn't science. We're talking about money and inventions
and technology. I noticed a big difference as soon as this
thing got to be something that somebody might make money on.
Oh, I hate to put this stuff in print.

Riess: I would have brought Gould up because you write that TRG

invited you to give a talk there. You say, "...we exchanged
ideas about work on spectroscopy of rare earth ions of the sort
that might be useful for optical masers. nl

Schawlow: Yes. Then they were still fairly open.

Also, in 1959 there was a conference that Peter Franken
sponsored on optical pumping at Ann Arbor. He called me up
just a week before and wanted me to come preside at a session
and give a talk. I didn't have time to get clearance from Bell
Labs, so I spoke rather obliquely.

Again, Gould was there, and he said, "We have six different
kinds of materials and a number of different structures, but

unfortunately this is all classified,
of it." [laughter]

I can't talk about most

Riess:

For the Shawanga Lodge conference in September 1959 Charlie
said, "Well, let's not fight in front of the Russians. Try and
say something nice about Gould." I did mention his idea of
using a scatterer instead of a mirror, which is okay but not
very important.

Was this the time that the Russians that shared the prize with
Townes were here?

Schawlow: Yes, they came to this conference in '59, the first quantum
electronics conference. That's the first time I met them.

But at this one in Ann Arbor I did tell about the ion pairs
and said they'd be useful for various kinds of masers without
indicating that I meant optical masers. Maiman was there and I
think he got some ideas from that. But I couldn't resist-
after Gould gave his talk, I said, "Well, your laser really is
more of an oscillator than an amplifier, so we should change
the "a" to an "o" in your entry into the optical maser race,
[laughter]

'ibid, p. 13A

165

Oh, I'd never seen anybody like that and I hope I don't.
But certainly in science that doesn't happen. Particularly
high energy physics where there are rather unique sharply
defined problems, there's some very dirty work goes on trying
to get publication before the other guy does. They have to
make sure enough that they have the results, but not wait too
long or other people will do it.

This book, Nobel Dreams, about Carlo Rubbia, who did get a
Nobel Prize- -when they were working on this thing that got them
the Nobel Prize, there was another group at CERN working on the
same thing. He met the leader of this other group and said,
"Well, we must be careful not to publish prematurely. Make
sure we really have a result." Meanwhile he had a courier
taking the manuscript to Physics Letters in Amsterdam. But
I've never had anything like that.

Riess: It's one thing if it has to do with real greed and money, I
suppose that's not okay. But if it has to do with academic
competitiveness, you're all in an academic world where it's
kind of dog eat dog?

Schawlow: Well, not for me, fortunately. But I think in high energy

physics it is that way. And in his case he got a Nobel Prize
and the other guy didn't. And that's very valuable, even apart
from the money involved. He gets all sorts of prestige.

In my world it's not that way. I have always said, "If
anybody wants to do anything that I'm thinking of, okay. I
have a lot more ideas that people don't think are worth
following up." As I've told you before, I'm really not a
competitive person at all. I'll go out of my way to avoid
competition. So it's a different world, different people.

Riess: Well, then the university is different from Bell Labs.

Schawlow: Bell Labs usually was not that way. It was only when people

smelled something that was really important that they began to
fight for it. Mostly they were very open and friendly.

In fact, what it took me a long while to realize at Bell
Labs is that they wanted to cover a lot of different topics, to
keep an eye--the purpose of their research, they claimed, was
just so that they would have a good view of all the frontiers
of any science that was related to their technology. So they'd
have just one or two people working on each area, so there were
a lot of lonely people around there. If you wanted some help
on something, you'd go to them, and they could drop what they
were doing and help you. It took me a long time to find that,

166

about five years, but certainly that's one way that Bell Labs
works so well.

Typically, a person gets an idea: he goes to crystal-grower
A, gets some crystals; goes to somebody who has equipment, B
and C; and then takes the results to theorist D. And you come
up with a paper with a lot of names on it. They think, "Oh,
Bell Labs has put a big group on that," whereas by that time
they're probably not even speaking to each other. So it was a
very good environment that way; it didn't seem competitive at
all.

They tried to make it more competitive. About the time I
was leaving they started clearly rating people in octiles,
giving bigger raises. When I was there people worked hard, but
they didn't work long. There was not a lot of this all-night
stuff which I gather there was in later years.

As you'll see in that movie [video], I really feltthere
were times I really desperately wanted to get the answers to
things, really wanted to know. But I had to learn to be
patient. When you have to work through studentsand some of
them are awfully slow you try and help them, but it just
didn't happen very fast.

Riess: So you become more teacher than physicist.

Schawlow: Yes. Well, more than hands-on. I didn't do very many

experiments myself, at all, which is probably a good thing
because I am quite clumsy.

167

IV THE EARLY YEARS AT STANFORD, AND FAMILY

Riess: You were at Stanford in September 1961. In the negotiations

for the Stanford job, did you have your NASA support? How did
that work?

Schawlow: No, I didn't. It was later. [laughs] Actually I was a little
naive. They did have quite a lot of money. They had Joint
Service contracts here, and I just kind of assumed that they
would take care of me and went ahead and ordered stuff.

I got the NASA contract after I'd been here a few months,
I've forgotten just how long, and they supported me until they
ran into hard times in the late sixties. And I guess I had to
admit that my stuff wasn't very closely related to their
missions. Fortunately, at that time NSF was growing and I
managed to get onto NSF. I had some support from the Navy all
along, and even a small grant from the Army Research Office.
But they, again, ran into financial difficulties and dropped
that.

Riess: How did you get the NASA money? Did you know people there?

Schawlow: No I didn't. I don't remember, tell the truth. I didn't know
anybody there. But- -gosh, I can't remember, somebody must have
suggested that I apply to NASA. I guess I talked with one of
their program officers.

I'm pretty naive. I didn't know much about how one got
money for research, but as I say, they had this Joint Services
contract. Money was still pretty plentiful then. Ever since
then it's been getting harder and harder to get.

168

The Department , Plain and Applied

Riess: How about describing the department when you got here, who the
other folks were and how you fit into it all.

Schawlow: You talk about negotiationsabout the only two things that I
had to make clear were, one, that I wouldn't come unless I got
a full professorship. I was forty by that time and I didn't
want to worry about having to get promoted. And there was no
problem about that, they said okay.

The other thing was that at that time the department had in
it a number of professors who had the title of "professor of
applied physics and electrical engineering." Their salaries
were split between the university and their research contracts.
The regular physics professors all had insisted over the dead
bodies of the administration that they had to be paid full-
time, and they were not going to charge any of their salaries
to contracts. Because they foresaw what happened later, that
when money got scarce some people lost their contracts, and the
university would have to find some way to pick up their
salaries.

I said I didn't want to be in applied physics and
engineering, I wanted to be just plain physicist, and there was
no problem with that.

It was a nice little department really, the smallest of the
good physics departments, I think, by a lot, I think they had
maybe fifteen permanent members, about five or so assistant
professors. But they were a brilliant group. Leonard Schiff
was the chairman, and had been for years. He was a theoretical
physicist, but he was a very good chairman and very democratic.
He kept things going nicely and was good at raising money for
his own research.

They had raised a lot of money. They had a lot of money
from the royalties from the klystron patents. The klystron had
been invented at Stanford by the Varian brothers, and they had
gotten money from the Varian Associates. Both the Varians had
died, but Mrs. Russell Varian gave money, as did the National
Science Foundation. They were able to put up a physics building
when the physics department had raised all the money.

Riess: The Varians taught here?
Schawlow: No.

169

Russell had gotten a degree at Stanford. I don't know
whether he had a master's degree or not. Russell apparently
was brilliant, but as Leonard Schiff once described, he thought
in a way in which logic was only a special case, [laughter]
They had given him and his brother Sigurd, who was an airplane
pilotthey were trying to do something to prevent airplane
accidents and one of them had the idea for this klystron tube,
which is a way of generating microwavesand they gave them a
little space in the physics building, which was the old physics
corner of the quadrangle. I don't know if they gave them money
or not, certainly not much. There they built the first
klystron.

During the war klystrons became important and the Varians
and several others who were later part of the applied physics
department Ed Ginzton and Marvin Chodorow they went to the
Sperry Gyroscope Company--! guess Chodorow hadn't been at
Stanford before thenand worked on klystrons during the war.
After the war, the Varians started this Varian Associates to
make klystrons.

Riess: Was there any question that Stanford owned this patent?

Schawlow: I don't know the details, but these patents were worth several
million dollars. They'd been obtained by Chodorow, Ginzton,
and their associates.

There are a number of threads here I have to tie up.
Shortly after I came I think Leonard Schiff got tired of
managing applied physics which was funded differently.

Schawlow: There was a lot of pressure to add more positions in applied
physics because it was cheap. Only a quarter of it came from
the School of the Humanities and Sciences, and the rest came
from engineering and government contracts. He really didn't
want to build up too much in that , have it overbalance the
department, so he pushed them into starting a separate applied
physics department. It has done very well, it's a very strong
department. Actually it's hard to tell, some of the things
they do there are quite applied; some of the things could very
well be pure physics.

Riess: So there's an applied physics department plus a physics
department.

Schawlow: Yes. And the physics department does all the undergraduate

teaching, which I think is in a way not so good. It meant that
we all had to do a lot of undergraduate teaching, whereas they

170

could just teach graduate courses in their specialties. I
taught very few graduate courses and I could 've learned a lot
more if I had had more time to work on that sort of thing. But
after a while they made the point that these klystron royalties
really had come from the people in the applied physics and not
from the physics people, so we had to give up our interest in
them. By that time they were nearly expiring.

Felix Bloch, Robert Hofstadter, and Bill Fairbank

Schawlow: Now, coming back to the physics department, the outstanding

person in the department at that time was Felix Bloch, who had
made a brilliant thesis in 1928 in which he set forth the
quantum mechanical understanding of how metals conduct
electricity. This really led to all the work on
semiconductors, which in turn led to things like transistors
and integrated circuits.

He had come as a refugee in 1933. He was Swiss, but he was
Jewish, and just felt it was better to get to a safer place.
He said he was visiting in Copenhagen, at Niels Bohr's
institute, when he got a cable from somebody named David
Webster offering him an assistant professorship at Stanford.
Apparently, this came up because I think the Rockefeller
Foundation had made up lists of brilliant European physicists
who might be refugees. He had never heard of Stanford and he
asked various people about it. Some of them had been there. I
think it was Pauli who said, "Jah, it was on the West Coast and
he had been there, and there was another university nearby and
they steal each other's ax." [chuckles]

Well, he came there, and Enrico Fermi, who was also both a
theorist and experimentalist, said to him, "You should do
experiments. They're fun." So he teamed up with Luis Alvarez
and they made a measurement of the magnetic moment of the
neutron, which was a brilliant experiment, and that was in the
late thirties. I think they did the actual experiment at
Berkeley, but I think he prepared some of the equipment.

Then after the war he started to look for nuclear magnetic
resonance, or nuclear magnetic induction was the way he did it,
and they did discover it in '46, I think, just about the same
time Ed Purcell and his group at Harvard also discovered it.
They shared the Nobel Prize in 1952, I believe.

It became apparent--. Well, I'll tell you a little more.
Bloch told me they used a big permanent magnet in their early

Riess:
Schawlow:

171

experiments, and they had to make the magnetic field very
uniform, so they put little iron shims on the face at various
places to even out the irregularities in the magnetic field.

He said they measured ethyl alcohol, CH 3 OH, and that he
found that the relaxation time was quite long. That meant that
the spectral lines should be very sharp and the magnet was too
crude to see that. So he said, "I just want to see a line that
sharp," and he kept pushing on his people to shim the magnet
better and make it more uniform. When they did they not only
saw a sharp line, but there were several lines. This was a
chemical shift due to the hydrogen being in different places --
some of them in the CH 3 would be one kind and the OH would be a
different one.

So this was the beginning of chemical shifts , and it soon
became apparent that magnetic resonance could be important for
chemistry. Varian Associates therefore decided they would
manufacture magnetic resonance equipment commercially. They
did and they sold a lot of them.

That's a story about the beginning of industry down here.

Of course, [Frederick] Terman had pushed various people into
starting companies, Hewlett-Packard particularly, and had
gotten Stanford to set aside this land for the Stanford
Industrial Park.

Riess:
Schawlow:

Anyway, Bloch was there, back to doing theoretical work;
after he got his Nobel Prize he gave up experimenting.

Also Robert Hofstadter, who had done brilliant work--.
When I came out here for interviews in the spring of 1961--I
was very impressed by what he'd done and he was very friendly-
he invited me to go salmon fishing with him on one of these
boats out of San Francisco. Fortunately he then got the Nobel
Prize and I never heard any more about that, [laughter] I'm
sure I would have been very seasick. He was a nice guy, and
unfortunately died a few years ago.

Then Bill Fairbank had just discovered that magnetic flux
in a superconducting ring was quantized. And that was a major
discovery.

Now say that again.

If you have a ring of superconductor, the current will keep
going forever and it'll hold whatever magnetic flux was in
there. But he found that it came in quanta. The value was
hc/2e: people had predicted this might happen, but the "2" they
didn't predict. This was one of the things that showed that

172

the electrons in a superconductor are paired, they act as
pairs. This later helped lead to the theory by [J.] Bardeen,
[L.J Cooper, and [J.R.] Schrieffer.

Well, Bill should have had a Nobel Prize for that, but also
apparently he delayed in publishing to make sure, and a German
named Nabauer published similar results about the same time.
Then Nabauer died, and I think because Nabauer wasn't alive to
get the prize, I think that may have had something to do with
the fact that he [Bill] didn't get it. He never did.

Fairbank then went on to do some grandiose experiments.
People said about him that he would find an experiment where
they needed to improve sensitivity by ten orders of magnitude
to do it and he'd get nine. [chuckles] Some of them didn't
work, but he did spark the construction of the superconducting
accelerator, and also the search for a superconducting
gyroscope to test general relativity- -which is still going on,
they still haven't flown it. It's supposed to have a space
flight sometime in the next few years, but the people have been
working on it some of them for thirty years .

[knock on door, pause]

Riess: We were talking about the department--.

Schawlow: Felix Bloch and Nabauer and Fairbank.

It was a wonderful little department.
Riess: What about Panofsky? You didn't mention him.

Schawlow: No. Panofsky had just decided that he would leave the

department and head up the Stanford Linear Accelerator Center.
He- -well, he tried to pull a few fast things on us. He wanted
to have professors there and said they'd Just be research
professors. Then he started demanding they should be allowed
to teach.

And SLAC

Schawlow: There was a good bit of friction between the physics department
and the linear accelerator center. Finally, they managed to
get President [Wallace] Sterling to assign teaching to the
physics department and SLAC professors could teach by
invitation, and we have always invited a few to teach.

173

Riess: He wanted to get his staff on salaries.
Schawlow: Yes, partly that, instead of just being paid by the contract.

Well, they have a large number of professors. We were
afraid we'd be swamped if they could do everythingthere "d
been a lot of fighting in the years just before I came as to
whether they would add a lot of people in the physics
department or not. Bloch particularly didn't want to have the
thing overbalanced by high energy physics.

Riess: So they have professorial rank and are only doing experimental
work?

Schawlow: Or theoretical, yes. There are about twenty of them, something
like thatat least as many as there are in the physics
department. They've done well. They've got three Nobel
Prizes, so it's been a success.

Again, I had the feeling that, as with the applied physics
people, they just wanted to teach the advanced courses and make
us teach the freshman stuff. And really, that's the way it
worked out, actually, they did teach mostly advanced courses.
That's what I was afraid of when I came, but I just sort of got
reconciled to it. It wasn't such a good thing.

We had to establish that the physics department's duty was
teaching. If we didn't have this duty, we wouldn't get any
staff. These other people are cheap, and the university would
rather hire them than get another person in physics. But if
the physics department has courses that have to be taught then
they have to give us some staffing. The physics department
didn't grow through the sixties at all, whereas in many
universities it expanded enormously.

Riess: Stanford, in a way, really has three departments of physics
then?

Schawlow: Some people put it that way and say we should somehow

rationalize them. But yes, there are three places where
physics is being done. Stanford is wonderfully disorderly.
There 're good physicists in electrical engineering and material
science and so on, and students can do theses with them. Or in
chemistry good physical chemists are quite good at physics.
So it's not hard for a student in physics to get a Ph.D. in
physics supervised by a professor from another department.

Riess: And that's not good?

174

Schawlow: No, that's all right. It means, of course, that we again have
to do the preparatory work and support them the first year or
so.

To tell the truth, it used to be at first that the
microwave lab was a place that we could dump the students who
were not awfully good. They might be good at experiments but
they weren't very strong theoretically. Now that isn't true
anymore. They admit their own students and they get very good
students, but sometimes some of them come over and do theses in
physics. I had a student who was in electrical engineering do
a thesis under me. So going back and forth is not bad. And
physics has so much affected technology in the last generation
or so that it's very reasonable that these places had to have
their own physicists.

Riess: What about Sidney Drell?

Schawlow: Drell had been a professor at Stanford. He went on a

sabbatical when I came, and when he came back he just decided
he was going to go to SLAG so he never really did quite come
back. It's too bad. He was a good teacher as well as a very
good theoretical physicist. But he sort of--well, he just sort
of treated the department with contempt. What really mattered
was just SLAC. So I had very little to do with them.

No, I sort of felt that I had come a long way, going
across the continent where I'd never been much, in order that I
could do research and teaching. While these people just sort
of had it easy. They could do all the research they felt like
doing, and teach when they felt like it.

Riess: Others who were in your position must have felt somewhat the
same way. It must have been a--

Schawlow: I think so, yes.

Riess: --gnawing debate all the time.

Schawlow: Yes, it was rather unpleasant.

George Pake had been here before I came, and he wanted the
physics department to start splitting salaries and build up a
big solid state group to balance the high energy physics. But
people like Bloch prevented that. He [Pake] left then. He
became provost of Washington University, where he had been a
professor before. That's Washington University in St. Louis.
He later was the first head of the Xerox-Palo Alto Research
Center.

175

Fortunately those fights were sort of coming to an end by
the time I arrived, but there were still problems getting SLAG
in its proper place. I went over and saw Panofsky when I came.
It was clear that he felt he had the backing of Terman who was
the provost, and that they were just going to do whatever they
wanted to do. He was not at all interested in trying to find a
mutually agreeable solution.

Riess: What did you go over to propose?

Schawlow: Well, to see what could be worked out, you know. As the status
of people at SLAC and--. Well, it was apparent by then that he
had gotten permission to have professors there. He was claiming
that well, professors are professors and he can teach when he
wants to teach.

Riess: Oh I thought perhaps you were going over to propose something
that was of an experimental nature.

Schawlow: No. Just try to find a better relationship.

Riess: Terman, as provost, was more involved than Sterling?

Schawlow: Well, yes.

Riess: Adjudicating all this.

Schawlow: Well, we had to go over his head and go to Sterling finally to
get it settled. But Terman was an empire builder, you know,
and he had gotten a lot of government-sponsored research and so
on. He was pushing expansion of that area. He was an
expansionist.

Riess: He wasn't a physicist, was he?

Schawlow: No, he was an electrical engineer. But he was provost, which
is sort of the chief academic officer.

Riess: Provost for the entire university not just a school.

Schawlow: Yes, yes, the entire university. But Sterling was president.

He was a very good president. He presided over the building up
of Stanford and raising standards. I think it was under his
presidency that it really became a great university, although
it had always had some respectability.

Riess: Then there was the other university on the other side of the
bay--

Schawlow: Oh, I've heard there was one there. [laughing]

176

Riess: Was there always the threat that one might defect to the other
camp?

Schawlow: No, there was I think a gentleman's agreement that they didn't
raid each other. I don't think that's in effect anymore, but
it really happens very rarely. No, but there are other places
in the country where one could defect.

Riess: If you went to visit Panofsky in the beginning, it's clear that
you saw what the situation was very early. But you decided
that you could live with it.

Schawlow: Well, we fought some to make sure that teaching was our

business, at least, and that they didn't have authority to
teach separately. I was on that side but it was a pretty
serious fight. I understood the issues very clearly. Bloch
and I were in complete agreement at that point.

The Big Picture: Teaching, Labs. Students, Postdocs

Riess: But the fight to teach some of the upper division courses?

Schawlow: Well, we really earned our living by teaching the introductory
courses, because those were the big ones with hundreds of
students in them, and that had to be done. Somebody had to do
it. We had a small department.

In fact we had a very good traditionstarted or continued
by Leonard Schiff--that the introductory courses were taught by
senior faculty. They asked me after I'd been there a few
months if I would teach Physics 21, which was Mechanics and
Heat for pre-medical students, without calculus. It was really
no more than a decent high school physics course. Well, I
might have been insulted except that Bill Fairbank was teaching
the second quarter of the Physics 20 series and Hofstadter was
teaching the third. With that company, it's an honor to teach.

Riess: That's interesting. Stanford could certainly say that our best
minds are teaching our students.

Schawlow: Certainly in physics. They had trouble in other departments.

I heard complaints that economics was having a lot of part-time
teachers teach the introductory courses while the professors
were all busy consulting.

Riess:
Schawlow:

Riess:

Schawlow:

[pause]
Schawlow:

177

You say that the loss to you in not teaching the upper division
or graduate classes is that you don't get a chance to get back
into that material?

That's right. I could have learned a lot of stuff. I would
have been forced to learn more advanced topics which I never
did learn.

Why are they things you didn't know?

Oh, there's a lot I don't know. I'm not very good at
mathematical stuff, as a physicist I'm really not awfully good.
Compared to the man on the street I'm pretty good, but I just
hadn't studied a lot of the advanced theory. And of course,
stuff was coming out so fast in the laser field, that if I had
been teaching it I could have learned more things, perhaps
gotten ideas from it.

I did teach a one quarter course in spectroscopy and
quantum electronics in alternate years for a few years. Then
after Ted Hansch came, he sort of took that over.

I should think that would be one of the reasons they wanted
you, was just because of this.

Yes, you'd think so, but it didn't work out that way. But I
did have a lot of graduate students. I built up very quickly.
I remember telling one of them sometime that I had ten graduate
students and never given a Ph.D. But then they started coming
out the pipeline and my students mostly finished degrees in
reasonable time. There were one or two that were hard to drag
through.

I had a lot of ideas, and I couldn't do them with my own two
hands. I wanted students to work on some of these ideas and
that worked pretty well at Stanford.

Well now, you asked about how I raised money [referring to
conversation during pause]. I was never very aggressive about
that. I guess I would hear that a certain agency had some
money and would take applications, and I talked with somebody
there and applied for it.

But I was careful not to get overcommitted. I didn't want
to commit to doing something I didn't want to do. I would
mostly only take money that left me pretty free to do whatever
I wanted, because generally whatever I proposed didn't work
out, usually there was something wrong with it. And it's the
things that I hadn't proposed that workedyou get an idea and

Riess:
Schawlow:

Riess:

Schawlow:
Riess:

Schawlow:

178

say, "Oh hey, let's try this." Really, that's the way it is
with me. I'm not a good planner.

What did you propose to NASA?

Well, I think just general work on spectroscopy and quantum
electronics.

You weren't proposing or developing the laser in six different
directions.

No, no. I didn't do very much on lasers then, it was mostly on
materials related to laser materials, trying to get at the
spectroscopy.

I remember one of the things that we did early. We had
observed these pair lines of chromium in aluminum oxide. They
had been known fifty years before, but not understood at all
what they were. But since we knew they were pairs, and you
could look at the crystal structure and you could see you could
have pairs in different directionsa pair along the symmetry
axis, or off in the side direction, or another side direction,
and we wanted to find out which lines belonged to which pairs .

So I had a student, Linn Mollenauer, working at applying
stress to the crystals in different directions, seeing how the
lines shift and which ones shifted the most. If you press
directly along the axis of that pair it would shift more than
if it was perpendicular to it. So he did some work of that
kind, which was, as I say, related to laser materials but not
really on them.

These were things that had been in your mind when you had been
at Bell Labs?

Yes. And others, of course, came up as we worked.

What does it mean to put together a lab?
did you have?

What kind of a space

I was very, very fortunate. At first I was over in what was
then called the Microwave laboratory. It's now called the
Ginzton Laboratory. I just had a couple of rooms there. But
then the new physics building opened and I think I had ten
rooms, I had most of the second floor, and so I was able to
expand fairly rapidly. There was enough money to buy basic
equipment, but I never really had quite enough money.

179

I had very few postdocs because I would rather spend the
money on students and equipment and only sort of accidentally
got postdocs if somebody came along. Actually I turned down
one very good man in the late sixties, I think '68, a man named
Richard Slusher. He was getting his Ph.D. at Berkeley and he
had an NSF postdoctoral fellowship. I told him I didn't think
we had a very good place, we were very short of money and
space. So he went to Bell Labs and has done very well there.

Riess: I thought postdocs did come with their own money, so why would
you ever turn one down?

Schawlow: Mostly not, mostly not. Mostly you have to pay them, and you
have to pay them more than you pay students. So I didn't get
many. Mostly you pay them from contracts, and I had fewer than
most programs do.

In 1970 I got this letter from Peter Toschek in Germany
asking if I could take a young man who had done his thesis with
him. Actually, they were sort of partners because Toschek was
just learning about lasers then too. Well, I wrote back, said
that I didn't have any money. He said, "Would you take him if
he got a NATO fellowship?"

I said, rather reluctantly, "Oh, all right." And it turned
out to be Ted Hansch, who was absolutely brilliant. We saw
that quickly and managed to find another hundred dollars a
month for him somehow. Fortunately, about then we got an
equipment grant from NSF and we were able to get some new
equipment. Wonderful things happened from then on.

But in the sixties there was one assistant professor, Peter
Scott, that I sort of inherited. Pake had hired him. He'd
gone off to England, to Oxford, for a postdoctoral year, but
they had this commitment to give him an assistant professor
ship. He worked with our group, but he did teach some too. He
is now a professor at the University of California, Santa Cruz.

Bill Yen, from Washington University, worked with us about
then. Yen is now a professor at the University of Georgia.
Warren Moos, who was here at about the same time as research
associate and acting assistant professor, is a professor at
Johns Hopkins University.

We did have another visiting scientist, Serge Haroche, who
came in 1972. He came from the Ecole Normale in Paris and was
very brilliant. He did beautiful physics research here, and
also after he returned to Paris where he is now the head of the
physics department of the Ecole Normale.

180

In 1977 James Lawler came from the University of Wisconsin.
He also had good independent ideas and the ability to carry
them out. He returned to Wisconsin and is a professor there.
He has received several awards for his research, particularly
in applying laser spectroscopic methods to study gas plasmas.

Then in 1981, when I was president of the American Physical
Society, the society provided half support for a postdoctoral
researcher. Steven Rand, who had already been a postdoctoral
researcher at the IBM Laboratory in San Jose, came and worked
on spectroscopy of ions in crystals with laser excitation. He
was enormously helpful, particularly in organizing the agenda
for the November meeting of the American Physical Society when
I was so occupied getting ready for the Nobel prize activities.
He is now a professor at the University of Michigan.

Riess: You mentioned having a couple of rooms. The experiments you
were doing could be done in a regular room?

Schawlow: That's right. We used one of them for kind of a workshop and
others for labwork. After Hansch came, he gradually took over
more and more of the space.

Riess: Our discussion of Stanford has started out with a run-down of
how it's divided up and all of that. And you said you went to
visit Panofsky. Does that mean that early in your time at
Stanford you got involved in administrative issues?

Schawlow: No, not very early, but these things were decided by the

department and the department had to be unanimous on them. I
didn't spend a lot of time on it, but I took positions on these
issues. I just went to talk with him [Panofsky] once, didn't
try again. In 1966, Leonard Schiff, after eighteen years,
decided that he'd had all he could take as chairman-- I think
the struggle to keep SLAC in its place had worn him down.

SLAC did do some things. They announced that Drell was
going to give a course in general relativity, I think, which he
was very well qualified to do, but still this was sort of an
end run around the physics department.

And Administration; Department Chair. 1966-1970 ftf

Riess: You were saying that in 1966 Leonard Schiff decided he'd had
enough of being chairman.

181

Schawlow: And I was foolish enough to accept the chairmanship. I

remember when I started I realized that practically every piece
of paper that came to me was routine, but I didn't know the
routines.

I was chairman for four years, and I was very glad to get
out of that. It was a lot of work. You had to know what
people to consult on various issues and make sure you did spend
time talking with them. The experimentalists were much
concerned about the workshop. The theorists didn't care at
all, but they cared a lot about the library. So you had to
spend time talking with people.

I don't think I was a very good chairman. I wasn't very
aggressive to try and expand, which we probably could have
done. But still, I did keep the lid on, and things were
reasonably peaceful when I was chairman.

Riess: Did the department have a strong tradition of journal groups
and meetings and symposia? Does the chairman keep alive? Is
that part of the job?

Schawlow: Well, you have to appoint committees. We would have a

colloquium committee, for instance, that would be responsible
for getting speakers for the colloquia. They'd have a lot of
other committees to do things. The chairman had to appoint the
committees and had to recommend raises for people, which was
difficult because there never was as much money as you'd like
to have. There I consulted with Leonard Schiff and we sort of
went over them together.

Riess: And sabbaticals, you had to decide on that as well?

Schawlow: Yes, but there usually wasn't too much trouble with that.

People usually had organizations that they could turn to for
funding such as NSF or other laboratories, and they had
postdoc's and so on to help cover when they were away. I don't
remember sabbaticals being a problem.

Riess: Were there any interesting people brought onto the faculty when
you were chairman?

Schawlow: I don't think so. As I say, I don't think I was very good at
going out aggressively and getting people. But we had no
encouragement to expand, and we had a good, strong faculty so I
sort of let it ride as it was. We did make a few offers. We
were trying to get an outstanding theorist, but the presence,
proximity of SLAC was a detriment.

Riess: Because that's where they wanted to go.

182

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

Either they wanted to go there or they were afraid that they
would be drawn into the discussions at SLAG. It just was
difficult and so we didn't get one man.

Interesting, I really had no idea that SLAC was such a black
hole.

Yes, it was difficult. Of course, if they went to SLAC they
wouldn't have to do any teaching, and they had a big group--
particle physicists seem to want to hunt in packs.

Felix Bloch especially objected to that. He felt that each
theorist should stand on his own. Well, it's a field where the
problems are fairly narrowly defined. Somebody gets an idea
and then everybody rushes to elaborate on that idea. Anyway,
it was not the kind of theory that Bloch was used to, and he
didn't like that. Nor, I think, did Schiff.

What about women and minorities?
in those years?

Were those important matters

No. No, they weren't. That's more recently we've tried to do
something about it. We did start making some efforts to get
minority graduate students, and we got some. But we didn't
have any women faculty at that time.

Do you mean on staff?

On staff, no, we didn't have any women on the staff. It wasn't
pushed pretty much. I think it's been more important later.
But the trouble is, frankly, if you have an appointment, and
you're not going to have another appointment in that field for
some years, you try and get the very best person you can, and
that isn't very often a woman or minority personbecause there
just are few of them, and chances are very great that if you
really have to get a top person, it won't be a woman or
minority.

There's also a

You were chairman of the physics department,
chairman of the applied physics department?

Yes there was.

Did these larger questions get chewed over between the two?

No, no, we didn't really have very much contact, and that's
probably my fault. Later on, people did try and get more
coordination between the two departments and they had regular
meetings of the chairmen I guess it was. But not at that time.
I just wanted to get on with doing some physics.

183

Riess:

Schawlow:

Yes. And in fact, you didn't need to say yes.
yes?

Why did you say

Well, I looked around, and either you do it or somebody else
will do it to you. [laughs] I just couldn't see anybody that
was any better. After I got out I sort of pushed for my
successor who, well, was only moderately successful. You have
a limited number people thereit was a small department.
However, they have managed and have had a succession.

I did one year as an acting head when my successor wanted
to take his sabbatical, and that was sort of a nightmare,
because one day some students came to me and presented a
petition that we recognize the graduate student research
assistants as a union [bargaining unit]. Research assistants,
mind you. This struck me as absolutely ridiculous because
these were just people who were being given some money to help
support them while they did their own thesis. But this thing
had obviously been drawn up by a lawyer, so I could do nothing
but hand it over to the university. I couldn't talk to them at
all, tell them that I thought they were stupid. I couldn't say
anything.

And it was probably for the entire university?

No, just the physics graduate research assistants. Well,
ridiculous. Eventually it got to the labor relations board and
they decided that it wasn't a sensible bargaining unit and that
ended it. But I had to deal with that.

Riess: Also you had some dealings with the free speech movement?

Schawlow: Oh God, yes. I was chairman of the university's research

committee at the time of the Cambodian invasion. The committee
had already decided that they wouldn't allow any secret
research that had been banned. There had been some secret
military research, in engineering particularly. They had
allowed that research could have some classification if it were
such things as needing to know the launch date of a satellite,
something like that, which was considered secret information.
But even that we had about decided to stop.

I had to go around with Bill Miller, who was then 1 think
vice provost for research, or something like that, and go to
departments like the music department and German department,
and explain to them what research was, let alone classified
research. The radicals wanted to stop all government-sponsored
research, all defense-sponsored research.

Riess:
Schawlow:

184

Riess:

Schawlow:

So why were you going to the humanities departments?
explain all this?

Riess:
Schawlow:

Riess:

Schawlow:

Riess:
Schawlow:

Riess:
Schawlow:
Riess:
Schawlow:

They didn't know anything about it, and it eventually would
come to a vote of the faculty senate. The issue was ending all
government-sponsored research, which would have been utterly
disastrous.

Were university-wide meetings called?

Yes, there was a meeting of the senate I particularly remember.
They'd had this research committee, and a subcommittee on
classified research, which was supposed to make sure that the
classification was only incidental and not really secret stuff.
The subcommittee had clearances, so they could see. One of the
members of that subcommittee got up at this meeting and
denounced the research committee for allowing classified
research. Oh! It was disgusting. I had to get up and point
out that we'd already stopped the classified research and
that'd only been incidental.

Was Stanford brought to a halt in the way Berkeley was?

Not as much. I think there were a few days. Leonard Schiff
was very active in going to talk with students and student
groups about things. There were some sit-ins.

Did you have anyone like Charles Schwartz?

No, nobody quite as bad as that. Charlie Townes was president
of the American Physical Society and had to contend with
Schwartz, who tried to get things done theresilly things.

However, we had Bruce Franklin who was an English professor
who actually incited the students, you know, saying, well, he
wouldn't turn his back on people who use violence, something to
that effectnot exactly telling them to do it, but sort of
encouraging them. Fortunately, they had long hearings
afterwards and they did fire him, which was a good thing. But
he was a pretty troublesome person.

Was he a professor?

He had tenure and everything, but they got rid of him.

Okay, so other issues while you were chairman?

Well--. You had to get unanimity for everything. There were
people who didn't like a couple of associate professors and
didn't want to promote them, but I managed to get these
reconciled. Frankly, I felt it was foolish to make a big issue

185

of promoting from associate to full professor. The guy has
tenure, he's going to be there anyway. So why do that? You
can still make his salary less than the person who's brilliant.
But I did smooth those over.

Riess: Is there a system of assessing teaching ability?

Schawlow: Yes, there is. We have to worry about that some, but as long
as it comes out adequately--. We have faculty members sit in
on other faculty members' lectures. And they have to put out
questionnaires at the end of every quarter for students to give
an assessment of the thing.

Riess: And they do that conscientiously, or is that just honored in
the breach, or whatever?

Schawlow: Well, we have had cases later on, not in my time. We had an

assistant professor who was a brilliant theorist but not a good
teacher. We had a very hard time getting enough good things
said about his teaching in order to get him approved for
promotion to associate professor. We did, but he decided to
leave anyway. He took a job at a national laboratory.

Riess: As you go up through the ranks do you teach less?

Schawlow: No, it's about the same all the time. Leonard Schiff had kept
the number of courses down so that we had reasonable teaching
loads. It didn't change.

Riess: Your research associates and teaching assistants would be your
graduate students?

Schawlow: Yes. The teaching assistants would be the graduate students,

not necessarily the same ones who were doing research with you,
but there would be a bunch of them assigned to each course.
They would have discussion sections and they would do all the
grading. I never had to do any grading.

Making up exams was always something I hated, though. I
did my best, but I found that when you have a big class, no
matter how carefully you word something, have it checked by
several people, there is always somebody who finds a different
way of misinterpreting it.

Riess: Isn't there a tradition of finding brilliant alternative ways
of looking at things?

Schawlow: Well, of course you're trying to do that, but when you have an
introductory physics class, usually they just misunderstand

186

what it is you are trying to say--even though you tried to word
it as clearly as you possibly can.

And worse than that, teaching these introductory
classes- -which I enjoyed in some ways because they had a lot of
demonstration experiments to do--you can't ask for anything
very difficult because it isn't a very advanced course. So you
have to keep repeating similar things, but you know that the
fraternities at least have files of the old exam papers. So
you have to try and keep finding something different. After a
couple of years it gets really pretty hard. I did keep
switching around different courses of teaching every few years,
but still making up exams was something I was very glad to get
rid of when I retired.

Riess: Do you think that there's been any anti-Semitism in the
department?

Schawlow: No, no. In fact, somebody who had been there as assistant

professor said, "That's a nice little Jewish department they
have there." And in fact they hadwell, Bloch, Hofstadter,
and Chodorow, for instance. But they weren't all Jewish. But
no, anti-Semitism, if there 'd ever been any, there wasn't any
when I was there .

There had beenI noticed at the University of Toronto when
I was a student, as far as I could see there were no Jewish
professors at the university before the war. There are now.
They just didn't--. It's not the virulent anti-Semitism that
you have in Germany, but well, they just didn't think those
were nice people to have around. Of course, a lot of the
Jewish people there were immigrants, fairly recent immigrants
from eastern Europe, and they were different, but they have
plenty of Jewish people there now.

At Stanford, by the time I arrived, it was not a problem.
I guess Bloch was probably the first one and he came in 1933,
so he'd been around a long time.

Riess: Yes, that's right. And the kind of scapegoating usually just

has in part to due with the fact that there's a lot of economic
pressure and so you look around and wonder who's getting it.

187

The Family

Settling into Palo Alto

Riess: In these last minutes, why don't you tell about how you settled
your family here.

Schawlow: I came out in April for interviews, and in May I decided. Then
I came out in June, and I had two days to find a house. We
found this house. It was an Eichler house.

Riess: Aurelia came out with you?

Schawlow: No. She couldn't. We had the three children then. But she
let me decide. And I figured this was a standard California
house. We could always sell it and move to something else.
Well, we never did, we got in there and Just sort of adapted
ourselves to it.

Riess: It was in a new tract then?

Schawlow: Actually, it was three years old. It was the oldest house in
that section of Stanford. They'd opened it up in 1958, and
Eichler builds faster than other builders, so it was the first
one finished. It had been owned by a librarian who had moved
to become head librarian at University of Nevada. Then it had
been rented by somebody, and it just came on the market the day
I was there because the renters had a daughter graduating from
high school and they wanted to wait until after she'd had her
graduation to show it.

I checked with Aurelia, it was all right, and I decided to
buy it. We paid just $27,000 which is what we eventually got
for our house in New Jersey. I sold it recently for $457,000,
so inflation has really taken place there.

Riess: Yes. Eichler houses were quite stunning, modern.

Schawlow: They're more open than I would have liked. I'd like to have
more closed-off sections. But it was all right. We got used
to it. It had some advantages. It had this radiant heat in
the floor, which is very clean and the floor was always warm in
the winter, so you could go around with bare feet. It was
built no worse than it had to be, and no better either, I
think. But it was well designed and well situated. Big
windows on the north and east sides, very small windows on the

188

south and west, which are the hot places. It was comfortable.
We thought of moving once or twice, but we never did.

Before we came we had hired an au pair girl from Sweden.
She went with Aurelia to Aurelia's parents' farm in Greenville
while the move was going on, because the house would be all
packed up, and I came out here to meet the movers. Ingrid [the
au pair] had a boyfriend that she'd met somewhere who lived
near there. I think the day she came here she called this boy,
and his father had died just that day, but he came to see her
anyway. They were quite friendly for a while, though
eventually she married a friend of his here staying in the
United States. Not the one that she'd known before, but a
friend of his.

The point is, we had this au pair girl, and she would work,
I don't know, five days a week, eight hours, something like
that. But I found I was spending thirty-five hours a week
taking care of Artie, and on the weekends and so on.

I had been approached by about eight different universities
that year, because it was the first year after lasers operated,
but the main reason we decided to come here was because of
Peninsula Children's Center. The Hofstadters had an autistic
daughter, and Mrs. Hofstadter had helped set up the Peninsula
Children's Center, which was at that time a school for
handicapped children that met in an old house way out in a back
part of Stanford. Here was a place for Artie to go. So
proximity was probably the deciding reason we came here.

Autism and Artie ff

Riess: You've said about Artie's autism that they didn't know that's
what it was.

Schawlow: They didn't know what it was and they didn't know what to do
about it, either. The name had only been invented, I think,
about ten years before he was born, and nobody knew much about
it. By the time we came out to California he had the label of
autism, but it didn't help much. There was no real government
funding for people with autism.

There was one juvenile court judge here who was willing to
make autistic people ward of the court in order to get them

189

whatever services they needed. We didn't have to rely on that,
but there was this day program that was set up in a house on
the Stanford property [referring to Peninsula Children's
Center] .

The first year Artie was there it was a good program, but
after that the woman who was running it left and Artie didn't
seem to take to it. He would go but he'd just sit off by
himself and not participate in anything much.

Riess: How did your respective families deal with this when you were
back on the east coast? Was there some sympathy?

Schawlow: Oh, yes, there was certainly sympathy. My mother was always
good with children, and she liked Artie. She would visit
occasionally and they would get along well.

Aurelia's parents were older; Aurelia was almost the
youngest in a large family. They did visit. Her mother, I
remember, visited us. Oh yes, we took Artie down there several
times and people were sympathetic. But he was little, and at
first you couldn't really tell whether he was slow starting to
talk or what it was, because he wasn't aggressive or anything
like that. He just was sort of a loner.

We really didn't know how bad it was until he got to be
about four or so. Then the only thing we could find in New
Jersey was a pediatric neurologist. She thought it was petit-
mal epilepsy, had some sort of an EEC taken, but I gather that
EEC's don't mean anything much at that age. And she prescribed
some kind of a drug for epilepsy. That made him incontinent,
and so he had trouble. He was going to a nursery school, or a
day care place. That was a difficulty. I think he had to
leave.

Riess: But having a name for his illness must have been some help.

Schawlow: Yes, it was I think. And later on it became a greater help
because there became funding for autism- -but that was much
later.

[sighs] Oh! At Stanford we consulted a psychiatrist, and
he didn't want to look at Artie, he just wanted us to talk
about what it might be that we were doing to unconsciously hurt
this poor child. After a few months I gave that up, though
Aurelia continued to go to him. But I think he was harmful.

We also went to a neurologist at Stanfordthey tried to do
an EEC, and Artie was upset, so they gave him a strong sedative
which I'm sure made the results pretty meaningless. Then the

190

neurologist thought amphetamines might have a paradoxical
effectthey sometimes doand calm him down. Instead, they
just made him more excitable and made him more locked into
doing things over and over, like jiggling shoelaces or sifting
sand.

He would do that for hours and he wouldn't eat anything
much. I forget- -he would drink orange juice, but I don't know
what else it was, there was very little that he would eat, but
somehow that turned out not to do any serious harm. But this
amphetamine was keeping him awake until one o'clock in the
morning, so I had to be up with him until then.

He liked to go for rides in the car, and go swimming, which
we'd been able to do in New Jersey, and also at Stanford when
they opened a pool. Then he got to running away, and we built
a big fence around the back yard and put in hooks on the doors.
But you'd forget sometimes and then get a call early in the
morning and he was in some neighbor's swimming pool. He wasn't
in any danger, but--.

So, we were kind of desperate. Molly Hofstadter had gone
to a place, Clearwater Ranch in Mendocino County, where they
had people who were supposed to have mental handicaps. (Well,
autism is kind of physical and mental.) We sent him there for
the summer when he was seven, and the next year we sent him
there to stay. That was a pretty good place for him. We would
visit him practically every week, and have him down
occasionally--! would go up and bring him down for the weekend.

Riess: Was there any kind of communication with him? From him?
Schawlow: Not really, no.

Riess: You must cut me off when it just becomes too intrusive, but for
me it's learning also.

Schawlow: Well, I may start crying, but I'll keep going.

[close to tears] Well was there any communication? No--.

Riess: You were speaking to him, I'm sure, all the time and the
question is--.

Schawlow: Yes, but we were not doing the things we should have. We

didn't tell him he was going to this place; we just took him
there and left him. We didn't know whether he could understand
it or not, we couldn't tell. He Just didn't show much sign--.

Riess:

Schawlow:

Riess:

191

He'd been up at this ranch for a couple of years and we'd
go and see him often, take him out on outings in the woods,
have a picnic or something like that. Or sometimes we'd bring
him home for a weekend.

But then there was a very nice lady, Grace Turner, who was
running what they called Townhouse. It was a house in the
little town of Cloverdale, right on the main street. She saw
Artie, and he reminded her of a boy with whom she'd had some
success, and actually had gotten him to begin speaking. So she
asked for Artie. Those were good years. He was there for
several years. And that's where he learned to read, he tells
us. He was ten years old. She taught him to read. But he
didn't show us at all. We didn't realize it.

Then when he got to adolescence- -they had young girls there
and they were afraid of him. I don't think he had been hitting
anybody then, but he began to have some tantrums and so they
felt they couldn't keep him any longer.

You mean at Grace Turner's house?

Well, Grace had left, I forget just why. The last year or so
there [at Townhouse] they had been taking him down to a day-
school program, but he apparently hadn't been participating
really.

Through all of this, the understanding of autism must have been
changing .

Schawlow: Yes, slowly.
it

Schawlow: Bernard Rimland--he' s a psychologist who was working for the

Navy in San Diego but he spent a year at the Stanford Institute
for Advanced Study in the Behavioral Sciences he wrote this
book in which he came out flatly saying autism was a physical
problem and not just the mother was not warm enough. 1 And the
people began to change their attitude toward it, but they still
didn't really know anything. People began to use behavior
modification, which is helpful in some cases, although it can
get too rigid if that's the only thing you do. You know, where
you reward good behavior and not bad behavior.

'Bernard Rimland, Infantile Autism, The Syndrome and Its Implications
for a Neural Theory of Behavior, Appleton-Century-Crofts, 1964.

192

But that didn't reach us, really, any of that. We tried to
find another place for him. Oh, several places turned him down
because they didn't know how to deal with autistic people.
There was one place that had retarded children. He just didn't
fit their type. Then we got into a farm near Petaluma. He was
there for some months, but again he was being very withdrawn
and not cooperating with the program, tearing up bedsheets,
things like that. So they kicked him out.

At that point, there wasn't any place to go but Agnews
State Hospital, or as it is now known, Agnews Developmental
Center. We went down there and they told us about all these
vocational programs they had. We thought, well, it might be
all right, but what they did actually was they just doped him
like a zombie, and they never had any vocational programs for
him.

[sighs] He was occasionally violent. He broke somebody's
finger, I think, slamming a door. I think they sort of were
very wary of him and really didn't do much for him. And it was
a terrible place, just terrible. Very noisy, with a lot of
other people and the bad things they did, like smearing feces
around. We tried taking him out. We tried taking him at home
for some weeks and getting somebody to take him to a day
program. Well, he hit that girl and she wouldn't do it
anymore. So back he went. We kept looking. We found a place
in Concord where they took him for a few months. And we were
paying for an extra person, but they still felt they couldn't
manage him. So that didn't last and he had to go back to
Agnews .

Finally- -Agnews was trying to get rid of him. We had
gotten a court order making us conservators with the right to
control his medication and got them to stop giving him drugs.
They were so angry at that they tried to kick him out, and they
tried to persuade us to take him to Napa State Hospital, which
had something that was alleged to be a program for autism.
Well, 1 went up there with Aurelia, and then Aurelia and Helen
went up there and spent most of a day, and decided that was no
good.

We asked the woman who was the head of the [National]
Autistic Society chapter in Sacramento, Marie White, if she
knew any parents of people at Napa. She said, "Oh, don't go
there. It's no good. But maybe he can get into this place
where my son is." This place was in Paradise. (And she had
had lots of fights with the authorities and forced them to find
a place for him.) This man in Paradise [Chris St. Germain] had
this school called Paradise School for Boys, which had
teenagers who were going out to day programs, to school, and so

193

on. He had admitted her son Doug White as a special case.
They got an exception.

Then he looked at how much they were paying for adult
autistic people and he thought he'd make more money. So after
some months he managed to get his license changed so he could
take adults and switch over to that. Well, he wasn't very
smart. He didn't realize that the adults required a lot more
staffing because they weren't in school all day. Artie had
been there just a few months and--

Riess: How old was Artie at that point?
Schawlow: I think he was twenty- seven.

After a few months, Mr. St. Germain came to us and said he
was going to have to close the place. He had broken up with
his rich wife, was losing money, and couldn't afford to keep
going. Well, we took a mortgage on our house and lent him
$100,000. It was about 1983, so--it was after we got the Nobel
Prize. We lent him the money and he kept going for a while.

We tried to get some sort of check on his financeshe had
an accountant looking over his figures, but she wasn't doing
her job, she would just take anything he gave her. He was
going through this [money] so that by 1985 he was running out
of money again. Apparently he had to admit that he'd been
dipping into his clients' money. I thought he was going to
lose his license.

But Marie White and I had set up a foundation, a non-profit
organization which we called California Vocations [Inc.],
because we wanted to provide some vocational training for the
people there. But we found we couldn't put money into this so-
called for-profit organization, we couldn't find a way. Well,
when we saw this trouble coming and he was going bankrupt
again, we had the charter changed so we could operate a group
home. By the early fall of 1985 we were told that if he [St.
Germain] stayed the income tax people would close it down
because he owed $58,000 in back payroll taxes. But if somebody
else took over, they would follow him for the money and let us
start fresh. So with essentially no warning at all, we took
over and he disappeared.

We took over, not knowing what we were getting into. We
had hired a lady bookkeeper, retired from one of the big
aerospace companies. She had tried to keep him straight but
couldn't. Then we got some friends from our church to help us
on the board and one of them straightened out the books. She
[the bookkeeper] had been treating the books like she might her

194

household expenses, not really keeping things well-budgeted and
careful. But we did get the books straightened out and hired a
new director who's still there, Phil Bonnet.

Riess: He had studied autism?

Schawlow: Yes, and he'd worked in several group homes before. He had a
degree in psychology and had worked in several group homes. I
think the regional center had not trusted Chris St. Germain, so
they didn't keep his place full. That was one reason he was
losing money. They took somewhat better to the new management
and let us fill up. He [Bonnet] has managed to keep the
budget balanced, although it's been very tight and we don't do
all the things I'd like to see us do for our clients. I've put
in a lot of money, given them a lot for very special purposes.

When Aurelia died, I had some stock that had gone up in
value and I gave them something like $125,000 to build a
recreation and training building, now known as the Aurelia
House. That was a success, they got a good builder and he did
a good job on that. Artie doesn't use it much anymore because
we rented an apartment in Paradise which we could use when we
went up there, and Artie comes down there nearly every weekday
when he has one-on-one. He blows up occasionally, and at one
point they got the regional center to give him one-on-one
staffing for five days a week.

Riess: The regional center administers the disability money?

Schawlow: Yes, that's right. There are nominally private organizations
that administer the state's money. They are, of course, very
much the creatures of the state. They have to do what they're
told. We are still supported by the San Andreas Regional
Center which is down in this area, and not by the Far Northern
Regional Center. The Far Northern has been rather tight in
providing extra services, and so I felt it was better for us to
stay where we were.

Riess: So he gets one-on-one--
Schawlow: --five days a week.

Well, they say he's doing very well. He has epileptic
seizures occasionally. They've been increasing in frequency,
which worries me a good bit, and I've been trying to find out
what's the matter. At one point where he had some bad
outbursts they got the psychiatrist to prescribe Haldol, a so-
called antipsychotic drug which has very bad long-term
consequences, and also lowers the threshold for seizures. I've
been pushing on them to cut down the dose and they have cut it

Riess:
Schawlow:

Riess :

195
some. I haven't gotten statistics lately of how frequent the

seizures are. But they used to be one a year,
been about one a month.

and now it ' s

So he does have a standard panoply of medications.

Tegritol for the seizures. Tegritol and Haldol are really all
he is taking. We've really made it clear that we did not want
him to be heavily drugged. And he seems all right. He doesn't
seem dopey like he did in the hospital. He really looked like
a zombie there. 1

Now, in addition to that, we have hired teachers to work
with him one-on-one. There was a nice young woman who worked
with him for maybe seven years or so, but then she got cancer
and diedno, it was longer than that, I guess, that she was
with him. It was only last year we hired new teachers. We
didn't know which one to hire. Artie sat in on the interviews,
and he didn't agree with Phil Bonnet, so we hired them both.
The one Artie preferred was the better one, I think. And I
hope she's still continuing. She took the summer off. I'm not
sure that she's come back. The other one did quit after a
year.

What are they working with?
facilitated communication?

Are they working with the

Schawlow: Yes, they've both learned to use the facilitated communication.

The one he had before, Lindaoh God, I'm so bad with
names he wanted to write with her. Just after we found out he
could communicate, we found he also could write or print.
Again, he wanted a hand on his. The way he did it was take the
top end of the pen while the bottom end was in his mother's
hand and manipulate it. With Linda he wanted to write and he'd
write with big scrawling letters, about one word on a page.
Apparently some other autistic people write that way too. I
think they have difficulty starting and also stopping a motion.
Although we've heard that you can use a squiggle pen which puts
a vibration on the hand. Some autistic people can write
smaller when they have that. We've tried it half-heartedly
with Artie. I have to see whether it's being used now or not.

'July 1, 1997. We have a new psychiatrist and a new neurologist. Art
is not taking Haldol, and the neurologist has added another drug to help
prevent seizures. [A.S.]

196

Linda didn't know very much mathematics. She took him
through grade school arithmetic. He already knew how to add
and subtract, but she showed him how to multiply things, how to
carry, and that about used up what she knew in mathematics. So
we hired a junior high math teacher to teach him more advanced
stuff. At one point, Artie said, "I can do so-and-so's baby
math, but I really want something more advanced." So we got a
man who was a lecturer in statistics at Chico State. He worked
with Artie, went through algebra and I think was even getting
into calculus. It's hard, though, to do, because Artie can't
write very much and you can only ask him questions which he'll
give you a yes, no, or a number for an answer.

Riess: He can say yes or no?

Schawlow: He'll type iteither type it or point to a card that has words
on it.

Riess: What impedes speech?

Schawlow: I don't know what it is, whether it's difficulty in initiating
it, or something is inhibiting it. But he has occasionally
said a few words very clearly. At the Autistic Society
convention last summer I ran into a number of people, about ten
or so, who knew at least one autistic person who just very,
very occasionally said something. So all the speech mechanism
is there, but they just can't produce it on demand, I think.

Riess: It is the most important diagnostic symptom?

Schawlow: Well, there's a wide range of autistic people. Some of them

can talk. Some of them use echolalia, where they repeat what's
been said and what somebody else said to them. Like if you
say, "Do you want to eat?" they'll say, "Do you want to eat?"
really meaning they do. But he never did that.

Failure to communicate somehow or other is a difficulty,
but there's a wide range. There's some people now who I think
are among the forefront who think it's a neuromuscular problem.
They Just can't control muscles that they want to do things. I
think there's a lot of truth in that.

Riess: What does learning algebra do for the whole personality?

Schawlow: I think it's something he wanted, he asked for it. He's

certainly much more relaxed than he used to be. In fact, Phil
Bonnet was mentioning that. He's participating more when they
have parties, he's not so withdrawn. Although I don't think he
really makes friends with the other residents. But he is quite
friendly with some of the staff.

197
Riess: They're all adults there?

Schawlow: Yes. I have a movie--well, there are a lot of movies with

Artie in them, but there's one--a film company from Luxembourg
was making a series of Nobel Prize winners. I told them about
Artie and they sent a film crew up to film him at Paradise.
They used it, I think, for some medical program in Germany and
Germanic countries. I have a copy of that film and also one
where Artie was working with Aurelia and me using facilitated
communication. There's also a video about Cypress Center in
which he appears occasionally.

Riess: Cypress Center was the name?

Schawlow: Oh, this Paradise School for Boys we had to take over on very

short notice and had to change the name because Paradise School
for Boys had a bad name. It was on Cypress Lane so we just
decided to call it Cypress Center. Turns out, we hadn't
realized that just up the road, hidden behind some trees,
there's Cypress Acres which is a large convalescent home. They
do get confused. Mail gets scrambled sometimes. Probably
should have taken a different name, but Cypress Center was one
that didn't describe exactly what we were doing. I didn't want
to do that.

Riess:

Schawlow:

Riess:
Schawlow:

You and Aurelia really got into the whole world of autism,
went to meetings.

You

Yes, we did and we learned stuff. [First] the Los Angeles
chapter of the Autism Society put on several conferences that
we went to. It was good to see other people struggling with
the same problems. We met some people there and got involved
with the Autism Society. We weren't in the beginning, but we
started going to their meetings. Met a lot of people and
picked up a few things here and there.

When Chris St. Germaine changed to this adult program he
hired Gary LaVigna, who was one of the foremost experts on
behavior modification for autistic people. He hired him as a
consultant, but they never did implement much of his program.
He also hired a very incompetent guy to be their psychologist,
and nothing happened. But LaVigna sort of pointed them on the
right track for a completely non-aversive program of behavior
modification, where they just reward good behavior and--

No punishment.

no punishment. No consequences other than what are
unavoidable: if you put your hand on a hot pot, you'll get
burned. That isn't punishment, but--.

198
Riess: Is much money going into research on autism?

Schawlow: I think there's more money now going into the medical side of
autism, and there's certainly no doubt that it is a physical
defect, at least caused by that. But of course, they have the
strange perception and difficulty communicating that can lead
to some bizarre behavior. I think there's not enough going
into the behavioral side of it.

There's a big program at Stanford looking into genetics,
trying to find out to what extent some cases of autism have a
genetic base, where in the genome that is. But frankly, I'm
not very interested in that because it isn't going to do any
good for my boy. There are people doing studies of brain, both
by magnetic resonance and also by autopsies of autistic people.
They slice the brain into small slices. They're finding
abnormalities and getting a general idea where they are,
although the brain is very highly interconnected, and so if
there's something wrong in one place, it may cause problems
elsewhere.

I guess I like to see anything going on in the medical
world, but I sort of feel that isn't going to help my son, not
going to happen soon enough. On the other hand, adopting a
teaching and somewhat behavioral strategy seems to help.

Riess: It gives him a life.

Schawlow: Yes. He's also held various part-time jobs.

Riess: How does he manage to do that?

Schawlow: Well, there's always somebody with him. They call it supported
employment where there is somebody there, his job coach, in
case there's any problems and also to show him how to do
things. They've been rather menial jobs. Some of them haven't
lasted long, not through any fault of his. He even worked for
a while as a dishwasher in a restaurant. He hated that
apparently, but the restaurant went out of business just about
the time he got really fed up with it.

Now he's doing some recycling a few hours a week. They
started a recycling program because the town of Paradise
doesn't have one. They distributed boxes and they go out and
collect the stuff in the boxes and bring it back there. Some
other residents sort it out. Somebody who's in the garbage
disposal business buys it from them. He likes that. He likes
going out. He's enjoyed emptying garbage pails for a long
time.

199

Riess: [laughter]

Schawlow: He used to do it too much. He'd throw out things.
Riess: Is he very strong?

Schawlow: Yes, he's quite strong. Yes, I couldn't stop him from doing
something he wanted to do. Fortunately this young man who's
working with him now is bigger and stronger than he is, and he
can handle him if there's any problems.

Riess: Is the young man who's working with him a professional?

Schawlow: He was in the Army Medical Corps for a few years and has

qualified as an emergency medical technician. He's studying
slowly to become qualified as a nurse. He's not in the full
nursing program yet, but he's been taking things like anatomy
and he has most of the requirements.

Riess: I realize how usually I turn aside when I see people with

needs. You know, maybe they have a cup out or something like
that. But you must have a whole different view of the world.

Schawlow: Well, I tell you honestly, and I've told other people, I really
am only interested in helping Artie. But I know that to help
him I have to help others. I have to keep this place going,
for one thing. I've had a lot to do with that and risked money
to have a place for him, and of course that benefits others
too. Because you can't just have him by himself. I've still
pretty narrowly focused on what might help Artie. I go to
these meetings. I pick and choose among the sessions.

Riess: I was just thinking that it's almost like a religious thing, a
kind of compassion.

Schawlow: Yes, well, you do have more sympathy for others. But I

couldn't see myself actually working with these other autistic
people. Certainly I do feel sympathy for other people with
autism. They vary widely. Some of them recover almost fully,
some of them are a little strange. Looking back, I know one
person I remember who may have had some mild autism. He was a
rather withdrawn sort of person. He worked as an accountant.
I met another young man who got a Ph.D. in mathematics from
University of Michigan. He tried teaching, but he just
couldn't do that because he didn't have enough empathy with the
students. So they come in all levels. Some are much worse
than Artie. But yes, I do feel sympathy.

I've tried very hard. We've brought in all the best
experts we could find to consult there. It's been very hard

200

because they really didn't want any outside interference and
they sort of run a minimum program. They don't hurt these
residents, but they don't really do nearly as much for them as
they could. Like each house cooks their own meals, but I think
the staff does the cooking. They should be training the
residents to do that because some of them will move onto semi-
independent living.

They have one girl who demanded to have a place of her own.
This is now the state's policy, to try and help people live as
independently as possible. So they did get a place for her.
Somebody checks up on her from time to time, probably every
day. I don't know just how it works.

Helen and Edith

Riess: Your daughters, Helen and Edith, did they manage to have a

normal upbringing in the face of all the concerns with Artie?

Schawlow: Well, yes and no. I think I neglected them. I was there, you
know, but I didn't play games with them or do anything much
with them. But there's nothing I could do about it, I just
did the best I could. But it was a struggle.

Riess: They've gone on to interesting careers.

Schawlow: Yes.

Riess: Were they very academic girls?

Schawlow: Oh, they were both pretty smart. Helen had a lot of trouble
with mathematics. She got interested in French. Her French
teacher at Castilleja, this private high school she went to,
got her interested in French and she was very good at that.
She has a very good ear for sounds. She could imitateshe
could say a word in several different ways, in different
accents, imitating different people.

I think the public school near us at Stanford was really
pretty bad. They should have drilled her more on arithmetic
tables earlier and she would have done better. Because I think
she's really not that bad. Now, she does arithmetic in her
head quite competently. She just got started wrong.

At this school, they combined fifth and sixth grades in her
last year there. So they were reading this silly book, Little

201

Britches, that she had read the year before in fifth grade.
Then she enrolled in junior high and they put her in with the
bonehead English class and the advanced mathematics class.
Well, I think they were going to read Little Britches again,
but at this point Aurelia decided to enroll her in this quite
good private school, Castilleja. That's in Palo Alto. And
there she did quite well.

Riess: Did Edie also go to Castilleja?

Schawlow: She went there for several years. Then she decided that she

wanted to be in a regular high school--maybe she wanted to meet
boys or something like thatso she went to Gunn High School
her last two years. But she went through junior high and the
first couple of years of high school at Castilleja.

Riess: And then where did they go on to school?

Schawlow: They went to Stanford. Fortunately, when I came there was an

arrangement where children of professors, if they were admitted
to Stanford, could get free tuition, but they couldn't get any
help if they went elsewhere.

Then about two years after I came, they changed the rules
so that you could have half of Stanford's tuition anywhere.
But people objected. I didn't, but they objected. So we had a
choice, and I chose to have full tuition at Stanford. I
thought that if they couldn't get in the Stanford, the state
universities are quite good here in California and that would
be okay. But fortunately both did get into Stanford and did
reasonably well there.

Riess: And lived at home?

Schawlow: No. They lived in the dormitory. But of course they would

come home quite frequently. It's only a mile or so away. And
they'd bring home washing.

Schawlow: Helen thought she might be a high school French teacher, so she
went to Berkeley to get an M.A. in French education. [She] got
very good training there through a very good man, Gian, an
outstanding teacher, and she learned a lot about teaching.
Then they sent her to do practice teaching in downtown Oakland,
and she came out one day and a big man stuck a knife in her
ribs and said, "You lay off my girlfriend." She didn't even
know who his girlfriend was, but that was the end of her high
school teaching career.

202

Anyway, she decided to finish her master's degree in French
there and came back and get a Ph.D. at home. By that time,
well, she and her mother got on each other's nerves, so we
bought a little house for her and she shared it, rented rooms
to a couple other girls, and lived there quite happily. That
worked out pretty well. Sometimes, young people do get on
their parent's nerves, and vice versa.

Riess: Let's finish off the rest of Helen's story.

Schawlow: She got a Ph.D. in French at Stanford and she feels she also
had some very good teaching experience here as a teaching
assistant. Professor Hester was her master teacher, and he and
Gian had written a book, an introduction to French, a first
year textbook. She did all the exercises, to check out the
exercises for them. So she was very well-equipped to teach
French.

But jobs teaching French were very scarce and I think maybe
she should have waited a little longershe started applying
for jobs before her Ph.D. was actually granted. You know, a
lot of people unfortunately give it [that practice] a bad
reputation by saying that they are going to get their Ph.D. and
they don't, but hers was quite certain.

She had gone with us to France on my third sabbatical in
1985. While she was there she spent a lot of time doing
research in French libraries and had good material for a Ph.D.
thesis on an obscure surrealist writer, Pierre Unik--U-N-I-K.
He had not written an awful lot, but he had been associated
with some of the more famous ones like [Andre] Breton. He also
had worked on films withwhat was his name?-- [Luis] Bunuel, I
think it is, the famous film producer, who had mentioned him
very enthusiastically somewhere and had said, "Why doesn't
somebody write something about him?"

Pierre Unik was one, when they had the split between Aragon
and Breton--! think Aragon was a militant communist and
follower of the party line, and he [Unik] went with him and
wrote mostly for party newspapers after that. He was captured
by the Germans and imprisoned during the war. I think he was
drafted into the French army. He wrote some poetry then which
people think is pretty good. Toward the end of the war he
escaped from a German prison camp, disappeared into the
mountains, and was never seen again, probably died.

Riess: Quite a tale.
Schawlow: Yes.

203
Riess: Did she publish it?

Schawlow: Yes. She got a little book published on that. It was a nice
piece of work, although she didn't feel she wanted to continue
that research. Now she's gotten very interested in French in
North America, and is thinking of doing a book on that if she
can get some time off. But it's very difficult. This
university has a foreign language department, and just has two
people in the French section.

Riess: Which university is this?

Schawlow: University of Wisconsin at Stevens Pointit's a branch of the
university. It's quite big, but it's mostly undergraduate.
There's only two people, so it's very hard for anybody to take
time off for a sabbatical. They don't have money to replace
them.

Riess: And she has a family?

Schawlow: Yes. But she has some ideas of possibly getting half-time off,
and perhaps that can be done.

Riess: When she thinks about North America, is she thinking back to
her Canadian roots?

Schawlow: Yes, well, Quebec and Louisiana. We went to Louisiana last

May. There was supposed to be a festival of French culture in
New Orleans, but when we got therethe whole family went she
decided that it wasn't worth bothering with, so we just kind of
explored New Orleans and then we went to the Cajun country,
Lafayette and New Liberia.

Riess: You must have loved the music.

Schawlow: Well, the music in New Orleans was good. Not great, but good.

Riess: I was thinking of the Cajun music.

Schawlow: No, I didn't hear any unfortunately. I don't really quite know
why we went there, except to see the places. We didn't really
get involved with the Cajuns, as such.

She has quite a collection of movies and records of the
various kinds of Louisiana music. There's Cajun, Creole, and
Zydeco. She knows the differences between all these. She gave
a lecture to the Wisconsin Association of French and Language
Teachers earlier this month, and apparently it was very well-
received. She had about a hundred people. She showed a little
film clip recording. She's very good at teaching. She had

Riess:

Schawlow:

Riess:

204

handouts for them, outlining how they could use this in a
classroom unit on Louisiana culture. She's very good at that.

But it's a tough Job, and getting worse because the
enrollment in French in high school is dropping and so they are
getting fewer who come with any high school French who would
become French majors. They've had a lot of majors, they're
second in the state or something like that, but if they come in
with no French at all, they really can't do a major. Well,
Spanish seems to be taking over the world. It has a reputation
of being easier. I mean, here it's useful. In Wisconsin,
they'd be better to learn French because there are a lot of
French Canadians just across the border, not only in Quebec but
in Manitoba.

Just one more remark: she wanted to show something about
these Cajuns who are working people, farmers and so on, to get
away from the image of French people, the perfume sniffers,
[laughter] But in fact, the students are really more
interested in France and French culture.

Our other daughter, Edith, is very bright, but never really
much of a scholar. I think she did very well. She majored in
psychology. Then she decided she would get a master's degree
in nursing from UCLA. She went there after she graduated from
Stanford in 1981. She had to take off a few weeks early in
December to go to Stockholm with us and she didn't go back. By
that time, she was very deeply involved with her boyfriend,
Bill Dwan, and they got married the next summer.

What's her last name?

Dwan, D-W-A-N. It sounds kind of Chinese but actually it's
Irish. I think it's a variant of Dwayne--D-U-A-N-E or D-W-A-Y-
N-E, but it's Dwan. When I was in Ireland later, I looked it
up in the phone books. There are two phone books for all of
Ireland, one for Dublin and one for all the rest of it. It's
not a big country. There are a number of Dwans around the town
called Thurl, it seems. Maybe there are twenty or so, not very
many.

We were on a sight-seeing trip, my wife and I, and in
Kilkenny we saw a truck and I almost swallowed my teeth because
the sign on it said "Dwan's Makes Better Dwinks." [laughter]
There's a soft drink company named Dwan and that's their
slogan. Unfortunately, I didn't get a camera out quick enough.
But later, Frank Imbusch sent me a couple of things with that
slogan on it.

So instead of getting her nursing degree, she--

205
Schawlow: --got married and has had three children.

Her husband was from a Catholic family. In fact, he'd gone
to a Catholic high school, and they were married by a priest
who had been his high school mathematics teacher. I expected
some difficulties, religious difficulties, but it didn't turn
out the way I expected at all. Edie had not been much
interested in religion as a childyou could drag her to Sunday
school, but she showed no serious interest. But they fell in
with some Baptists and before you knew it, they were both being
baptized in a Baptist church, a rather fundamentalist group.

Riess: Where is this?

Schawlow: Well, they lived in Menlo Park at that time. They had a house
in the country, in Woodside I think it was, where some
neighbors were Baptist. Then they lived in Los Altos for a
while. Then they got really deeply interested in religion.

Bill wanted to do something to help religion. He had
gotten a dual major or he'd gotten a B.S./M.A., I think, in
biology and mechanical engineering. He thought he wanted to do
something in prosthetics, or something like that to help
people. He came from a rather wealthy family. His great
grandfather was one of the three founders of the 3M Company, so
he has a good bit of money, so he can do what he wants. He did
work for the Veterans Administration but I think he found that
they were treating him just as a technician, rather than part
of the research team, doing programming. Then he took a job
with Lockheed doing programming for a while, image processing
for space missions.

But then they said they wanted to do something with
religion, so he got this job with a company called Walk Through
the Bible, whose office was near Charlotte, North Carolina.
It's actually in South Carolina, in the former PTL complex,
this outfit from Atlanta has rented a building there. They
were preparing materials for teaching Christianity and the
Bible, making movies and other educational materials. He was
doing some computer work there and he liked that quite a bit.
That's why they moved to Charlotte, North Carolina. Houses
there are cheaper. You can get a huge house for what he sold
his house here.

But just recently this year, that company has closed that
office, decided that they couldn't afford it anymore, and he's
now taken a job as a science teacher in a private elementary
school. He enjoys the work. He may decide to get a teaching
credential later. As I say, he can afford it, he doesn't have

206

to work if he doesn't want to. But he's a very conscientious
guy and wants to do something worthwhile.

Riess: And what is your daughter's role in all of that?

Schawlow: Well, she has three children which keeps her busy. But she
also has gotten very deep in it and she's teaching a Bible
class in this church of a small denomination whose name I
forget. It's an offshoot of the Lutheran. Anyway, she teaches
this Bible class every week I think, and does a lot of work
preparing for it. I'm sure she does a good job.

They don't seem to have any desire to come back to
California. Charlotte is a nice town. It's growing very fast.
It has a lot of big new buildings. It has a lot of things;
there's a fine science museum, a concert hall, good hospitals.
It's a pleasant city. It reminds me of Toronto when I was a
boy- -you know, a moderate size city, not a megalopolis like New
York. So they seem happy there. I think Bill doesn't really
know what he's going to do eventually. He's an engineer at
heart, I think. He's very good at fixing things, and
apparently a good programmer, too.

Riess: We haven't mentioned Helen's husband.

Schawlow: Oh, yes. His name is Tom Johnson. He comes from a Swedish
American family. Of course, Jansen is a very common name.
It's spelled J-0-H-N-S-O-N, but the Swedes would pronounce it
"Jansen." They're very, very proud of their Swedish heritage.

He got a Ph.D. in anthropology from University of Illinois,
and he's on the faculty in anthropology at this university
[University of Wisconsin at Stevens Point] . They met at
Stevens Point and got married and they have these two
daughters. He's a very intelligent man and has diverse
interests. He's wonderful at getting along with people.
Indians was his specialty, American Indians, and he
participated in the Sun Dance with the Shoshone tribe. He
really gets their confidence. But he tends not to publish very
much; he's a perfectionist who can't finish things off. So
he's not famous, but he's a good anthropologist.

Riess: I wonder about fame, the theme of fame in your family, and how
your daughters have loved or resisted that.

Schawlow: Well, I can't say much about that. I mean don't know much.

Things were the way they were. I think they enjoyed going to
the Nobel ceremonies, but I don't know. I don't think either
of them had any interest in going into physics or doing

207

anything with physics. If I had had more time with them as
children, I might have played with them more, with Meccano or
something like that, gotten them interested in mechanical
things. Edie probably would have had the talent to do that
sort of thing if she wanted to, but she never did really.

You know, after Artie was such a disappointment, I never
felt ambitious at all for the girls to do anything particular.
If they're just reasonably normal, that's good enough. I never
pushed them at all.

So, is that enough about that?

Riess: That is enough, yes. Did you have any graduate students who
were girls?

Schawlow: I had a few, yes. One of them, Antoinette Taylor, she was
really quite bright and good at measuring things. One day,
though, I was getting a bit worried about her. I had suggested
some things that she might build, to improve the apparatus, but
she didn't get around to it. I said, "Look, if you go on like
this and never build anything you're going to end up in the
traditional woman's position of taking measurements for some
man. So you really ought to build something." She took my
advice and did build an electronic circuit that they needed for
the experiment .

Riess: And so that was a breakthrough for her.

Schawlow: I think so, a little bit, yes. She had all the ability she
needed. She got married then to a theoretical solid state
physicist, and they're both at the Los Alamos Laboratory in New
Mexico. I saw her briefly at a conference in Baltimore a year
or so ago, but I turned away to get a cup of coffee and never
saw her again. [chuckle] Too bad. It was one of these big
meetings.

Riess: But can you actually make someone into a physicist? From your
accounts of your own childhood, you were a physicist from the
minute you could lift a pencil.

Schawlow: I don't really know. I presume that anybody who comes to be a
graduate student in physics has some interest, at any rate, and
you try and find out what their abilities are. Some of them
are really not at all creative, and they're just not going to
be real physicists. They may be good at doing exams as
undergraduatesoh, they're so different, there's such a
tremendous range of abilities.

208

Riess: I was reflecting on your comment about doing more with your
daughters. Do you think the early education is essential in
setting the stage for the development of a future physicist?

Schawlow: Well, it could help.

Arthur Schawlow at Columbia in 1949.

Arthur Schawlow with a laser consisting of a rod of ruby cooled by liquid
nitrogen and excited by light from a flash lamp reflected by an elliptic
cylinder reflector. Stanford, 1962.

Arthur L. Schawlow, 1991.

209

V WORK AND STUDENTS

Secrecy, Motivation. Morality
[Interview 6: November 7, 1996]

Riess :

Schawlow:

Riess:
Schawlow:

I think I asked you much earlier in these interviews what it
was that bothered you about Joan Bromberg's book, which seems
like an authoritative report on the laser in America, but let
me ask it again, now. 1

There are two things about the Bromberg book that seem to me
less than satisfactory: one is that she somehow has the fixed
idea that the military were orchestrating everything in this
field, and it wasn't true at all. They did supply some money,
but they really didn't initiate anything. When I was at Bell
Labs, of course, they didn't look to the military for money.
We didn't take any outside funding. At that point we could do
whatever we wanted to do--as long as it seemed relevant, in
some way, to communications.

And I think also she gave a little too much credence to
Gordon Gould who really contributed almost nothing to the
growth of lasers. He had a lot of stuff written in his notes
from time to time, [from] which he managed to get patents. But
everything that he revealed later had already been found by
other people. Those are the things that bothered me.

How did you work with her? She interviewed you?

Yes, she did. I guess
of my articles. There'
Bertolotti.

I gave her what materials I had, copies
s a rather better book by an Italian, M.

J Joan Lisa Bromberg, The Laser In America, 1950-1970, MIT Press, 1991

210

I will say that the parts of the Bromberg book that I
didn't really know anything much about, like the semiconductor
lasers, seemed better to me. [laughs] I guess it's always the
case that when a reporter, or even an historian, writes about
things that you really know, it's never quite right.

But she really is wrong on the motivations, at least for
the early work. We just had no thought of military interests
at all, really. It was a classic problem, really, like the
search for the origin of superconductivity. This going from
longer to shorter waves, and trying to get still shorter, is
something going on through the whole history of radio from the
beginning of this century--and one with which I was certainly
very familiar. I think Charlie was too. I never gave death
rays a thought, and I really expected that the first laser
might produce microwatts or something like that. Whereas I was
really very surprised when Maiman's first laser produced a
kilowatt in short pulses.

The military did start putting money in there. They wanted
me to get a clearance and serve on committees, but I knew that
if I accepted a clearance, I'd have two problems. One is that
I would know things that I couldn't share with my students,
which I didn't want to do. The other thing was that it would
take a lot of time. I'd probably have been on every laser
committee in the country. So I just refused to get a clearance
until much much later, when I did get one to serve on the
National Research Council's Committee to study ways of
preventing forgery of currency using color copiers. That, I
thought, was a worthwhile project. I don't think we solved the
problem, but we made some suggestions.

Our report had to be secret, of course. Still, some of the
things we discussed are already in place, like the threads in
the paper, and also some fine print. At the moment there's
fine print on the higher currency, the hundred dollar bills and
so on; there's fine print around the picture which is too fine
for the current generation of copiers to copy. But that won't
last, and I know they're in a running battle with the color
copiers. It's so easy for a person who has something he can't
share, like a girlfriend he doesn't want his wife to know
about, or a drug problem, to just put a twenty dollar bill on
the office color copier. You can get away with some amazingly
bad currency if you pass it under the right conditions.
Anyway, that was around the late eighties. But up until then I
wouldn't take a clearance at all.

Riess: How did you work on that problem? Did you get together as
group each time?

211

Schawlow: Yes, yes, we had a few committee meetings. I didn't do any
work outside of the committee meetings. Brian Thompson of
Rochester was the chairman. I got off it after, I don't know,
a couple of years when they did our first report. But I know
that the committee did continue.

Riess: So the new Hamilton hundred-dollar bill reflects all of this?

Schawlow: Well, some of the things that we talked about, not everything.
It probably has some things that we don't even know about.
They try to have secret [features]. There are some very good
counterfeiters, a gang in East Asia that has moved from country
to country apparently makes very good copiesthey even know
where to put magnetic ink and so on.

Riess: Well, it's probably a field worth studying.
Schawlow: Yes, there's money in it. [laughter)

I really never got very deeply involved in military things
although you heard a lotpeople would come and tell me things.
In fact, many years later Elliot Weinberg, who was working for
the Office of Naval Research and supervised some of our
contracts, said, "You know, there never was anything going on
that you didn't know about." I think that's so. I really have
the opinion that military secrecy usually hides incompetence,
at least when it's military research.

They had a project to make a hundred joule ruby laser,
which cost a lot of money and didn't lead anywhere. They were
trying to get weapons right away and the state of the art just
wasn't there yetmaybe it isn't even now. It was satisfying
to me that one of the first applications was for medical uses,
for surgery on the retina of the eye. But I have very
ambivalent feelings about the military. I don't like the idea
of wars and killing people, they don't make any sense, but I
know they happen. And I remember, of course, very well World
War II when we were really faced with some horrible evil that
had to be fought, in Hitler. In that case I was willing to do
my small part, but generally I think it's a waste of time, most
military research.

Riess: In 1969 you published a paper in Physics Today called "Is Your
Research Moral?".

Schawlow: Oh yes, I have to talk about that next week. I foolishly let
myself be inveigled into giving a presentation at a seminar
that some undergraduate has organized on scientific ethics.
He's gotten all the Nobel Prize winners around Stanford to each

212

take one session, and mine comes up next week. I'm really very
reluctant to talk about that.

Riess: What did you say in the paper?

Schawlow: Have you ever seen it?

Riess: No.

Schawlow: I'll get you a copy of it.

What I said essentially was that people try to blame
scientists for the consequences of their research, and that's
ridiculous because you can never know what other people will
add to what you have done. You just can't really predict the
consequences, both good and bad. You just have to have faith
that the good consequences will somehow outweigh the bad ones.
And that's quite different from development, say, when you're
trying to build an atomic bomb . I think people knew what they
were doing. On the other hand, discovering the properties of
nuclei, the people who did that clearly couldn't accept any
responsibility for what was done with it.

Of course, we just mentioned the example of lasers, where
people talked right away about death rays, it was a very old
idea from comic strips and fiction, but that wasn't what the
lasers were like at all. In fact, there have been many good
consequences. When I was in Akron and had the pleurisy, Dr.
Bird bought one of his respirators and gave it to me because he
was grateful because lasers had been used to do an operation on
his wife that would have been very difficult without them.

I still think that in the case of lasers there 've been all
sorts of different applications that surprised me. I couldn't
hope to imagine them because I don't know the needs in a lot of
these different fields. The progress of lasers in many
directions has been quite spectacular. Science is cumulative:
everything that one person does is there as a foundation for
other people to build on. Having said that, it's about all I
have to say.

Riess: Do you think that the ethics debate, or discussion, will end up
being very challenging?

Schawlow: I don't know. Of course, they have people there who are in
biology and medicine, and well, they have different problems.

One of the things about physics is that the results have to
be reproducible. If you faked a result, people would find out,
and that's a quick way to ruin your reputation. In some other

213

branches of physics, particularly high energy physics, it's
extremely competitive because there are only a few machines and
they're narrowly focused on a few problems. And there, some
really dirty work goes on to try and beat out the other guys
who are working in that field.

That really doesn't happen in the things I do. As I have
told you, I am really one of the least competitive people you
ever saw. Unless there's a student that is committed to a
particular project, I would just as soon move out of the way
and do something different if somebody looks like they're
competing with me.

Uses of the Laser. Unusual and Medical

Riess: A number of things come to mind from what you're saying. First
of all, having seen the Science in Action video, there's a
charming part where you come in with a potato that your wife
has suggested could be more efficiently peeled by laser. Was
that in the spirit of emphasizing that it's benign?

Schawlow: Well, yes, I did a lot of stuff to show that lasers were really
not the death rays. That's one reason I invented the laser
eraser, which workedand I even got a patent on it, at the
urging of our contract monitorbut it never got used. But
here was something you could build. People were talking about
these death rays that you couldn't build, and here was
something you could build. If it had ever gone into mass
production, it could have been practical to have one built into
a typewriter. If you make a mistake, you bring it back to
where it was typed, press the zap key, and off it would go.

I didn't intend to patent it or try to make anything of it,
but I just wanted it as an example of something you could do.
I thought people might take up the idea, but they didn't.
First of all, IBM brought in the sticky tape for erasing and
then word processor computers really took over.

Riess: Could that ever have been cheap enough? The zap of light? I'm
figuring that zap of light's got to cost something each time.

Schawlow: Yes it does, but for a secretary's time when he or she only has
to take out a few letters, a few characters, it would be cost
effective. I had a letter from a newspaper publisher who
publishes the Army Times, wanting to know if you could use this
for de-inking newsprint for reuse. I did a rough calculation
and said I thought the cost of the electricity would be more

214

than the cost of the paper, even if the lasers cost nothing and
were a hundred percent efficient, which they weren't. So it
wouldn't have done for that.

I did have a chance to make something out of it: National
Geographic was, of course, very careful with their books, but
they put out one book and they had right in the frontispiece a
picture--! think it was either Arizona or New Mexico, but they
had put it in the wrong state and they wanted to know if I
could erase a hundred thousand copies of this thing. Well, I
wasn't set up to do that. I think it could have been done, but
I hadn't engineered the thing.

Riess: You mean it could have been done through the layers?

Schawlow: No, you'd open the page and zap the thing that you wanted to
get out. It wouldn't take very long, just open the page.

I also got some interesting correspondence. There was a
man up in Oregon who was in the lumber business, and he wanted
to know if you could use lasers for cutting wood. I wrote back
that yes, you could do it, but the lasers we had were too small
and inefficient. He said he knew that, but he was trying to
look ahead to see what could be done in the future. He was
saying that in cutting trees sometimes they'll hit a hard part,
or somebody may have put a nail in the tree, and that'll break
the saw blade and maybe cause a dangerous accident. He thought
the lasers would be better. He was right in a way, but the
question of timing--! don't know, I think he died before he got
a chance to do anything on that, a few years later.

It certainly is good to look--. I felt the applications
have to come mostly from the people who have the needs . And
the eye doctors are a great example. I think I've probably
said already that neither Charles Townes nor I had ever heard
of a detached retina. But the doctors knew about them, and
they knew that they could prevent detachment by putting in a
flash of bright light. Originally, I think somebody in
Switzerland started it with sunlight. And then they used xenon
arc lamps. The laser was a brighter light that could be very
sharply aimed. So they knew what to do with it right away, and
within a couple years of the first lasers they were beginning
to use ruby lasers for preventing retinal detachment.

Riess: What does it do? How does it work?

Schawlow: It puts a little scar tissue on that sort of welds the thing

together. The retina, I understand, is not really attached to
the back of the eye. It's just pressed against it by the
fluid, and if it develops a tear then the fluid can seep in

215

behind it and lift it off, and then you can't focus. In that
case, the eye doctor has to go in and turn the eye in the
socket and come in from the back. They can do it, but it's a
fairly serious operation. But if they get it in time, they can
prevent it by using a laser.

The ruby laser wasn't ideal for that purpose. It had an
advantage that it didn't hurt, but it wasn't absorbed strongly
enough so that sometimes it would penetrate too deeply and
rupture a blood vessel, in which case the surgeon would have to
take over. But it still did save quite a few people's
eyesight. I think Bob Hope was one who had a laser retinal
operation.

Riess: So the lasers that end up in the hands of the surgeons get
developed for that purpose by some middle person, not the
physicist?

Schawlow: Yes, yes, that's right. And I know one company, Optics

Technology here in the Palo Alto area, did develop one of the
earliest lasers for eye surgery. Dr. Narinder Kapany, a very
inventive person, was the president of that company, and he
worked with a couple of eye doctors here, Dr. Christian Zweng
and Dr. Flocks. There were others, other places, but they were
one of the first to do it.

I'm not an engineer. I couldn't have done that, I don't
think. Well, if I had dropped everything maybe I could have.

Riess: But you can have a lot of roles in this business. You can be
the physicist. You could possibly be the engineer. You also
could be the entrepreneur, the developer. There are lots of
directions that come out of all of this, and it's interesting
that you stay clear of them.

Schawlow: Yes, I didrather deliberately. I know there were a couple of
students in the business school who wanted to form a company to
make laser erasers, and I wouldn't have anything to do with it.
They were going to raise money.

But if I'd taken on that responsibility, it would 've been a
full-time job and I wasn't really sure of success, that I could
make it practical. Well, you just have to choose, all the
time. It's hard. I mean, sometimes you make mistakes. I've
certainly made mistakes. I made a bad mistake in not trying to
build the first laser, which I did know how to do but I Just
didn't push it, I had a lot of other interesting things to do.

216

Riess: Do you know yourself well enough to know what really "powers"
you, as it were? It's not money, I guess. Money being often
the thing that powers people.

Schawlow: Well, as they say, "Money is maybe not the best thing, but it's
a long way ahead of whatever 's in second place." [laughter]

I guess I have to realize my limitations. I know myself
pretty well, but I never can tell when ideas will strike and
they may be quite a different direction than what I've been
doing. So I enjoy getting at new ideas and trying them out.
I'm not sure that I could undertake a linear development job
where you have to do one thing after another.

[telephone interruption]

Schawlow: That call was from the new home where Artie lives. They have
some problems. They have one young man who's been there for
ten years, but lately he's started wandering into somebody's
house nearby and they got very upset. They tried various
thingseven put one of those alarm things on his wrist, or
ankle, I don't know. But they've been unable to keep him in
there, so they're trying to find another solution, try and rent
a house somewhere that he can live in by himself for a while.

Riess: Why do they call you about it?

Schawlow: Well, he called me about various things. I'm a member of the
board of directors. I'm vice president, I guess, and was
really one of the founders of this place. But he also called
about Artie, wanting to know if I was coming up this weekend.

Riess: Now, you were saying that you didn't feel that you were the
type to be doing a kind of linear development thing.

Schawlow: Yes. Well, I don't know. I've never really done it. Maybe I
could do it. Didn't really want to.

Riess: Do physicists do this? Do they drop out of basic research?

Schawlow: Oh, yes, sure. Lots of them do because there aren't that many
jobs in basic researchit' s a great privilege to be able to do
basic researchso a lot of them go into industry, and lot of
them do jobs like that. I have one student who was in various
research labs, and he lately was in Livermore. Then he took a
job with a company that makes semiconductor lasers. But they
want him mostly to do sort of sales engineeringcontacting
customers and that sort of thing.

217

Funding and the Military

Riess: Back to Bromberg: one of the things that was interesting to me
was the it's just so obviousthe amount of money that started
flowing in and becoming available.

Schawlow: I think a lot of it was wasted.

Riess: One example, though, is ARPA funding TRG.

Schawlow: Yes. Well, TRG and Gould probably did have more insight that
lasers could be powerful. In fact, they got the Air Force to
support them before any lasers were made after our paper came
out. Gould made a deal with them to give them his patent
rights, to license them under his patents and give them rights
after on anything else he did. But he kept delaying giving
them his initial stuff so that he had more stuff that was his.
They [TRG] tried to get the Air Force to classify all the work
on lasersthis was before anybody had made a laser and we
simply told them that if they did that, we would stop working
on it. They didn't.

Riess: What was the dialogue? Who got in touch with whom about that?

Schawlow: I don't know the details, but I think it was initiated by TRG
and the Air Force. Which one started it, I don't know. But
then somebody, I don't remember who it was, somebody at Bell
Labs got word that that's what they were trying to do.
Certainly my reaction, and I think others at Bell Labs, said,
"Well, if you're going to classify it, we're not going to work
on it." Because we wanted to do publishable things. We were
trying to build up our reputations in physics.

Riess: But the ABM defense idea?

Schawlow: Oh, that was later, I think. That probably was one of the

goals, yes, but that was so far beyond anything, that nobody--.
1 don't know what went on in the military circles Charlie
would know better than I on that but I would hope that they
had more modest goals than that.

Riess: Well, that's the way Bromberg explains ARPA funding TRG,

because they were looking for ABM defense "Though no laser has
yet been demonstrated, lasers were even then being taken into
account. . . Ml

The Laser in America, p. 82.

218

And that leads to another book, The Physicists. 1 It's a
book about physicists in America. The period we're talking
about is a period of big money where it's hard to imagine greed
not being a real factor.

Schawlow: It really was. A lot of people started going into physics
because they thought they could make big money. A lot of
physicists took jobs with companies or started their own
companies. Oh, a lot of stuff went on.

I had a friend who, a few years earlier, had gotten his
Ph.D. at the University of Toronto. I guess he had a teaching
job for a while, but then he went with a company that was
started in Cambridge, Massachusetts. There was a Harvard
associate professor who found that several of his students were
getting more money for their initial jobs than he was making.
So he decided he was going to make a fortune and he started
this company, hired a lot of people, and then sold it after a
year or so. And it did make a lot of money because he just had
assembled a staff --and although they'd never made any profits.

There was a lot of that. It really didn't touch me much.
At Bell Labs we didn't have anything to do with government
funding. Not in our department. Bell had a military division
at the Whippany Laboratory, but it didn't touch the basic
research.

Riess: What about the meetings at exotic locations, jet-setting
around, and good salaries at the universities, then, too.

Schawlow: Well perhaps. Certainly, well, I don't know how much that
affected--. Of course, there were a lot of people at the
universities who took jobs where they were paid mostly or
partly by government funds .

There 'd been a battle at Stanford. The engineers were into
that heavily and engineering at Stanford had grown very big and
very good. Our electrical engineering was either the best in
the country or maybe MIT some years would be rated better.

Riess: That's why they could offer so much.
Schawlow: Yes, and could hire so many.

'Daniel J. Kevles, The Physicists, The History of a Scientific
Community in Modern America, Harvard University Press, 1987.

219

Riess: The glamour field was high energy physics, which accounted for
only one out of every ten physicists, but had a third of the
federal funds.

Schawlow: Well it's a very expensive field, and still is. Of course,
they turned out Ph.D.s there who couldn't get jobs in that
field, and some of them became computer programmers because
they had been heavily engaged in computer programming in that
field. And some of them went into different fields, I guess.
Some of the people who got their Ph.D.s in high energy physics
went into lasers because it was growing and had money in it.

I remember a meeting in 1963 at Brooklyn Polytech. The
excitement there was really palpable because there were a lot
of people there from companies who wanted to know how they
could get into this laser field. As I say, I think it was
overblown but it was there all right.

Riess: And by the end of the sixties, well--.

Schawlow: Money was getting scarcer. Even when I started in '61 there

wasn't as much money as there had been a few years earlier when
you really could fund anything. But we managed to find some
money to do some researchthat was from NASA mostly, and we
had small amounts from the Navy and the Army. By the end of
the sixties NASA decided that they had to be more selective in
what they were doing and they couldn't support us. Fortunately
the National Science Foundation was growing and we were able to
get in there and get about the same amount of money from them.

Riess: It was not just NASA. The whole country at the end of the

sixties was taking a strong dislike to science, whereas they
loved it in the early Kennedy years .

Schawlow: Yes, well, it isn't just a dislike to science. I think there's
a disenchantment with higher education. Perhaps that came a
little later, butthe trouble is that universities had
expanded so much that they were turning out an awful lot of
people. And there simply were more educated people than there
were jobs for them.

I think in the early seventies they made some manpower
projections that the teaching at every level, from grade school
to college, was saturated and there really weren't going to be
any large influx of jobs in teaching for a long time. For
centuries that was the chief place where university people
went. So I think there began to grow a disenchantment with
higher education, which was so expensive, getting more
expensivefaster than the cost of living.

220

I think we're feeling that now and going to feel it more.
There was one big disappointment: people thought, looking at
the demographics, that there were going to be a lot of people
to be educated in the nineties because there was sort of a
second baby boom, but it hasn't happened. They thought the
universities would have a lot of replacements and openings, but
instead they've been squeezed in budgets and they're cutting
out programs. Prospects for university teaching are not very
good unless you're exceptional.

Riess: That's interesting. So [in the sixties] there was that and
then there was the whole bad odor of the military industrial
complex.

Schawlow: We had very good relations with the military.

Riess: No, but I mean the swing against science, don't you think that
had to do with the military ties?

Schawlow: Well, one of the problems was that the military, the Navy
particularly, had taken a very far-sighted view that they
wanted to have good relations with the scientists in case some
emergency came up and they needed to enlist them the way they'd
done in World War II.

They also wanted to sponsor far-out work that might
eventually lead to something more dramatic. You know, the
question: do you want to improve the sights on the rifle or
build an atom bomb? They had that sort of attitude. Partly,
yes, they wanted to have good relations with the scientists.
They were very good to work for. They didn't try to interfere
at all and they had people in their liaison jobs who understood
what we were talking about. They didn't try to make us justify
everything.

Now Senator Mansfield was worried about the growing
influence of the military on universities, and he put through
thisthe Mansfield Amendment, I think it was called, which
required that every project they have at the university have a
specific military purpose. And that was really pretty harmful.
Well, it didn't hit us very directly because certainly anything
having to do with reconnaissance or communication served a
military function. Work with lasers, I think, fitted into that
pretty nicely without having very specific weapons-related
things. But it was typical of the timehe was doing that
because he felt that universities were getting too cozy with
the military.

Riess: And that that basic research was not--.

221

Schawlow: Yes, that they didn't always have clear military applications,
which was, in my mind, a perfectly sensible way to do it .
because you couldn't know what was going to come out of this
basic research.

But they did support what was then high energy physics.
For instance, the high energy physics lab at Stanford which had
a one billion volt accelerator, on which Bob Hofstadter did the
work for which he got his Nobel Prize, that was mostly
sponsored by the Navy. Of course, they had advanced
accelerator techniques. It was the first big linear
accelerator and it helped in the development of large high
power klystrons, spurred the development.

Riess: Nibbling at the edge of the ethics issue is what the goals are.
It sounds like it comes with the territory, doesn't it?

Schawlow: Yes. I guess so. Well, my attitude has been expressed in that
movie. I think I said that you do science because you think it
may benefit mankind in some way, but when you're actually doing
it you have to put all that out of your mind and concentrate on
the problem itself. If it is basic science you just really
can't try to aim it at a particular problem.

On the other hand, it's true that money is available for
some things and not for others. And it was available to some
extent for lasers because they had, I guess, military
application- -and one that I never thought of, which actually is
the real one, was the target designators, where the plane will
send a laser beam at a target and the bomb will home in on
that, either from the plane or from somewhere else. I
certainly had no idea of that.

Whereas there was not that much money for some other things
like maybe cosmic rays--I can't think of examplesacoustics,
for instance, things that were not considered very important.
Certainly there was money for underwater sound sort of things,
ultrasonics, but not, say, for musical acoustics.

Riess: Did you come down on one side or another of the space
exploration questions? Have you spoken out?

Schawlow: No, I avoided them. In fact, I didn't even get in a public

debate on Star Wars, either, although unfortunately when Reagan
made his announcement I think Time got hold of something I'd
said a few months before about the impracticality of those
things. But I didn't say anything more than that.

Riess: And were you a member of the Jason Group?

222

Schawlow: No, they really were after me and I did go to a couple of their
sessions. I think I went twice for a day when they were
working on some problem. My work was strictly unclassified and
I didn't get involved in anything secret.

Riess: That was your reason, that it would 've compromised your ability
to--

Schawlow: work with my students. I guess when it comes right down to

it, I don't like having to keep secrets. I like to tell people
what I know.

Riess: When you were on the phone with the administrator of the place
where your son Artie lives [Cypress Center] it made me think
how much you would like, probably, to have made lasers work for
him in some way. Have you thought about that?

Schawlow: No, not really. I've often thought it would be nice to have

some kind of a laser operation on myself, but fortunately I've
avoided that. [chuckle] No, I couldn't see that lasers were
going to help.

Riess: I mean for some of the technology for learning.

Schawlow: Well, I did spend a good bit of time trying to use computers

[for Artie] without very much success. But I just never could
think of any way that I could use lasers for him, so I didn't
give it much thought.

Riess: You say you weren't thinking about retinal surgery and yet it's
such a wonderful result. Does your imagination run to problem
solving or do you stay at the basic level?

Schawlow: I try to stay at the basic level. I'm really interested in

fundamental questions in science. No, I don't think much about
it. I've been on boards and I've been a consultant to several
small companies, but I really haven't contributed much on the
technical side. If I do any good, it's mostly from steering
them away from crazy things --but not a lot of that, either.

Facilities at Stanford

Riess: Last time we talked about some of the physics faculty at

Stanford. A couple of others--! don't know whether they're
relevant, but you didn't say much about the Stanford Microwave
Lab and Edward Ginzton.

223

Schawlow: He was already pretty much out of there. The president of
Varian Associateshe'd been associated with them from the
beginning- -but the president was involved in a plane crash and
sort of didn't have it any more to really lead the company. So
Ginzton had to take over as president or chairman, I'm not
sure. By that time he wasn't spending much time around the
university, so I didn't work with him.

Riess: Did the microwave lab continue?

Schawlow: Yes. Oh yes. It's now known as the Ginzton Laboratory. I
guess somebody gave some money to rename it. It has been
expanded some and it's a good lab. I worked there for a year
or so, I think a little more than a year, because the old
physics corner was very crowded and the new physics building
was planned, but I think they finished it at the end of "62 or
'63. And then I had lots of space and moved into the new
physics building.

But my contracts were still administered by the microwave
lab for many years because they had a very good contract
administration. They also had a very good machine shop, which
has unfortunately has had to be cut down over the years. They
had a good drafting department, too, which is all gone. Now
everybody does their own drawings on their computers. I don't
think they have any drafting at all. If they have to get
something drawn, they would send it out somewhere.

Riess: It sounds complicatedthese little fiefdoms and labs.

Schawlow: Well, the Ginzton Lab had a building- -it was the microwave lab
then. Had some good people there. Tony Siegman was there, and
he wrote several good books on masers and lasers. There were
some people who had been working on masers and switched to
lasers. Siegman had some very good students. One of his
students was Steve Harris, who was so good that they kept him
on the faculty there and he's done very good things. And one
of his students was Robert Byer who also is on the faculty.

Riess: When you came here, it was partly the attraction of the
microwave lab?

Schawlow: Well, not really. It was a place for me to work. I never

worked very closely with any of those people. They were nice,
and we'd talk occasionally, but they were--. I don't know, I
was always interested in something different.

Riess:

Another one I wondered about was Henry Motz.

224

Schawlow: Yes, he had built a far infrared or sub-millimeter wave

generator using an electron beam. He had left, I think, by the
time I came here, he retired. I thought it might be
interesting to do something with that, but people around there
felt that it was a dead end and they wanted to take it apart
and use the space. So I didn't push on that. They were good
people, but I never worked very closely with any of them.

What I think was more attractive was that they had people
like Bob Hofstadter and Bill Fairbank in the physics department
who were doing really outstanding physics. I just wanted to be
in that sort of an environment, even though I wouldn't actually
work with them on the same problem. But they were people who
understood the process of discovery since they had made
important discoveries themselves.

Riess: And that was the environment that was really lacking at Bell
Labs?

Schawlow: No. They had good physicists at Bell Labs, too. The thing

that was lacking at Bell Labs was that they wanted to cover a
lot of fields and do nothing very intensively. It's the same
thing that Charlie Townes remarks, that they were quite happy
to support what he was doing, but they wouldn't let him expand
it. So you could do what you could do by yourself with one
technician, or occasional collaborations with other people, but
you couldn't really get a lot of people working on your ideas.

Riess: What happened to Ali Javan? Did he stay on at Bell Labs?

Schawlow: No, he went to MIT. He stayed at Bell for a while, then he
went to MIT fairly early. For some years he didn't produce
anything. He's still at MIT and has some good work going on,
but he doesn't seem to getting around to publishing it. He did
some very good things at MIT. I remember one of the military
liaison people said that he's a real national resource.

Riess: I see. You were still at Bell Labs when Ali Javan was there.

Schawlow: Yes, I was there when he, [Donald R.) Bennett, and [William R.]
Herriot got the gas laser working. But he [Javan] came in
there, spent a lot of money right away. He was going to work
on liquid helium and he bought a cryostat and a big magnet, and
never used them. He got interested in lasers and had this idea
of a gas laser and he managed to persuade them to let these
other two people, Bennett and Herriot, work with him.

I remember there was a time when the management was getting
worried. Sid Millman, who was the department head, came around
and asked me whether I thought this was going to work. They'd

Riess:

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

225

had some results in measuring some gain, though not for laser
action. I said, "Oh, yes, I'm sure it's going to work." I
guess other people said the same thing, so they continued it,
and it did work.

In Charlie's book, Making Waves, in one of his chapters he
talks about the interaction between pure and applied science.
Last week, when we talked about Stanford, you really made those
distinctions quite clear here.

Yet it's nice to be able to move back and forth. I think some
places they would have called what I was doing applied science,
but we didn't have to make that distinction. I certainly would
distinguish between engineering and physics. And in fact, I
really don't know what applied science is. I think, at best,
it's just applicable science, science that has some fairly
obvious application to some problem in technology. Certainly,
science benefits from technology, just as technology benefits
from science, so we could get advanced equipment at various
times. Of course, the rapid rise of digital measuring
equipment is one example of that, although that didn't really
come in until the seventies.

Did you have meetings,
sciences?

or tea with your equivalents in applied

Yes, there was a seminar. For a while, I organized a seminar
in lasers and a lot of people came to it from companies around
and that sort of thing. I guess Siegman probably took that
over. I stopped going to it. We had our own group, people who
were working for me. We would meet once a week and I would
have various students talk about what they were doing and have
discussions there. We did that even at Toronto, and certainly
Charlie did that very successfully at Columbia.

But this was a way to get the applied science people together
with the pure science people?

That first one was, to get various people together. But I
think I sort of came to the conclusion that it didn't really
have a lot to offer me, directly. Of course, in the beginning
I was interested in everything that had the word laser or
optical maser in it. I used to collect every scrap of
newsprint, newspaper, or anything like. But then the field
just grew so rapidly, you couldn't follow everything; you had
to realize what it was you were doing and what you weren't
doing.

So I sort of drew back into myself rather than trying to
communicate with the others. What they were doing wasn't the

226

same thing I was doing and my work in the sixties was mostly on
spectroscopy related to laser material. We did a little bit of
work with lasers, but not an awful lotusing lasers for
scientific stuff.

Riess: I have to ask you whether diamonds wouldn't have been just the
most perfect thing in lasers.

Schawlow: Well, they don't work. They have some advantages, but pure

diamond wouldn't emit light anywhere near the visible or have
any absorption bands. It's quite transparent way out at the
ultraviolet. Now, most gem diamonds have various impurities,
so they will glow. Diamond, I think has been made to lase
since then. Yes, I think Steve Rand at University of Michigan
did get diamond to lase. But of course, they're very small and
their optical properties differ from one kind to another. I
think they just didn't have the right absorption and emission
characteristics for lasing action.

Riess: But they're hard.

Schawlow: Yes, and that really became apparent, that it was important to
have something rather hard or it wouldn't stand up to the
thermal shock when you fired them.

It was not possible to grow diamonds at that time, and you
couldn't put in the right kind of doping the way you can in
sapphire. Artificial sapphires and rubies had been grown for a
long time and they knew how to put various impurities in them.

"Science in Action" and Other Honors

Riess: Why were you chosen as the quintessential scientist for the
"Science in Action" program? Tell me about that.

Schawlow: I really don't know why they chose me for the scientist. It

may be that I had a reputation for being entertaining, being a
fairly good lecturer, and I had done something important. But
I don't know. They didn't discuss it with me. And I don't
know who made the decision, really.

"Science in Action" was a program produced, I think, by the
California Academy of Sciencesyou know, the museum in Golden
Gate Park. Dr. Herrold was the organizer and he was the master
of ceremonies. They had me on there in January, 1962, just a

227

Riess:
Schawlow:

Riess:

Schawlow:

[pause]

Riess:

Schawlow:

few months after I came. That was the time Frank Imbusch and
Linn Mollenauer, my two students, went with me and we had a
crude laser to demonstrate.

I guess I found that I could break a blue balloon with it
and thought I would demonstrate that. But the students put on
the balloonit was a sausage-shaped balloon which was standing
uprighta hammer and sickle and Sputnik or something like
that. I was rather horrified but I thought, "Oh well, maybe
you won't be able to see that." Fortunately, it worked. If it
hadn't worked, it might 've been bad. But when I saw the
kinescope later, they had zoomed right in on the thing and you
could see it relatively clearly. But I didn't emphasize it in
my talk.

That was made in the worst possible way for the performer
because they broadcasted it live and did a kinescope, a film,
which they then rebroadcast other places. So if you made a
mistake, it would not only be shown live but would be repeated.
But I didn't have any feedback on that. That was 1962. By
late 1965 by that time the show had been running for some
years and they had decided to have an independent producer
produce it. He was the one who approached me and asked if I'd
like to do this. I said okay. He was in charge of it. It
didn't have any direct connection with the Academy of Sciences.
They were nearly at the end of their run; I think they were
going to finish in a few more shows .

Did it have commercial sponsorship and all of that?

No, I don't think so. It was on Channel 9 and some other
educational tv places around. The guy who produced it did get
an award for it from some national organization, but I never
heard the details of exactly what the award was.

I thought it was perhaps like an earlier version of "Nova."
No.

Also in the early sixties you received the Ballantine Medal.
And the Thomas Young Medal.

Yes, and then in '63 I was at a meeting and one of Charlie
Townes' former students said, "You don't think you're going to
get a Nobel Prize, do you?" I told him truthfully that I'd
been nominated but I didn't know. Then in October of '64, the
university newspeople came and said they'd gotten a tip that I

228

was going to get it and share it with Townes and Maiman the
next day. So they came and took pictures in my class. I told
the class that I didn't know what it was for, which was not
true. I then told them truthfully that the last time they'd
taken pictures in my class, it had appeared in the university's
annual report as an example of expenditures. [laughter]

Riess: [laughs] You're good!

Schawlow: Well, it's true. But then I had a kind of sleepless night.
Turned out they gave it to Townes--with [Nikolai] Basov and
[Alexander] Prokhorov, the Russiansfor the maser/laser
principle. And you can't split it more than three ways.

After that I thought, well I'm not going to get one. I'd
stopped worrying about it- -hadn't been worrying about it much
anywayjust go on and do my thing as best I can. When it came
seventeen years later in '81 I was surprised to find that they
had given me a Nobel Prize for contributions to laser
spectroscopy.

Riess: Oh dear! Does this make sense, the first award?

Schawlow: Well, they can only include three, you see. As one of the
Nobel committee people told me many years later, he thought
they'd made a mistake including the laser in that. Because
they could 've given it just for the maser.

Riess: Including the laser really does include you.

Schawlow: Yes, yes. So when they gave it to me, in the announcement

they have some committee member make a little speech. He said
that the step from the maser to the laser was made by Schawlow
and Townes, something like that. So I don't know.

Also, in talking with one of the Nobel people, he said that
it had been a close thing. It could be that the committee may
have recommended one thing, but then the Academy may have
overruled them. They can do that at the last minute. It isn't
official until the Swedish Academy approves it. But I don't
know.

Certainly the Russians had been lobbying hard. In fact, at
the Quantum Electronics Conference in Paris of 1963, Basov came
up to me and said, "I'd like to discuss with you and Townes who
in this field should get the Nobel Prize."

Riess: Was this being funny?

229

Schawlow: No. He was dead serious. So I sort of joked and said, "Well,
I'm pretty sure I know who Charlie Townes thinks should get the
Nobel Prize"--meaning himself, of course, which he should. But
I don't know Just what all they did. The Russians do tend to
lobby.

I couldn't object. The maser did come before the laser,
and it was an important step, although what the Russians did
was less than what Charlie had already done. But they got it
in print first. Anyway, so I just forgot about getting a Nobel
Prize. I remember telling peopleseveral times people asked
if I had a Nobel Prize, and I explained why it had been given
for the maser /laser principle, that the maser had come first,
and so I wasn't going to get one. I was pleasantly surprised
when they did find a way to give me one. They did share it
with Bloembergen, who had invented the tunable solid state
maser which was the important one for radar and communications.
He shared it with me and he was also overdue, I think.

They do a great job, I think, with the Nobel committees.
They had this Nobel reunion in 1991 to mark the ninetieth
anniversary of the Nobel Prize. I was talking there with one
of the people who had been on the committee when I got mine,
and I was saying I thought the committee had a great job. He
said, "Oh well, we made some mistakes." [laughter]

Riess: It can't help but be somewhat political.

Schawlow: Well, I certainly never lobbied for it. I was really quite
surprised.

Some Russian Physicists

Riess: The old view of Russia and the Cold War was such that when
Charlie talked about meeting with Basov and Prokhorov I was
shocked, or titillated, because the Russians were such
"nonpeople" to the ordinary citizen of this country.

Schawlow: Yes, well Charlie tried to make friendly relations with them.
I think he really believed that the scientist could do some
good by talking with the Russians, because they could
communicate on some level. And he was probably right on that.

We did have some Russian visitors. We actually had a
couple of Russians work in our lab for a couple of months, I
guess three months each. We were quite friendly, but I never
talked about politics or anything like that with them.

230

Riess:

Schawlow:

Riess:

Schawlow:

But this country was fighting the Cold War.
feelings about that?

What were your

I never went to Russia. I heard so many horror stories about
how unpleasant it was. At one point, I got an invitation from
some ministry of machinery, or something like that, to go and
give talks and I consulted the CIA to ask how I should respond
to that. They said, "Write and ask them if you could visit
some laboratories." And I heard nothing more from them after
that. But then later there were scientific meetings held
there. Of course, Basov and Prokhorov did come to the first
Quantum Electronics Conference, and we met other Russians at
other conferences-- [V.S. ] Letokhov and Chebotayev were among
them.

Chebotayev was a very nice person. Everybody liked him and
he was a very good scientist, too. After the Soviet breakup,
when things got so very poor, support for science and
everything in Russia, University of Arizona was trying to hire
him. I think he had about decided to go there, but then he had
a heart attack. In fact, he was there visiting and had a heart
attack, and died. Not very old, fifty-ish I think.

Letokhov is quite a bright guy, very ambitious, and I think
quite powerful in Russian science. More of an operator than
Chebotayev was, but they're both very good scientists.

And what about the political system, what about communism?
it the scourge that it was made out to be?

Well, I never had any doubt about that. I had no use for
communism, even back in the thirties, I just couldn't see how
anybody could fall for that.

It was interesting: at least one of our visitors told me
that he had read some books here that he couldn't read at home.
Maybe Gulag Archipelago, I'm not sure. I didn't try to draw
him out on that because I felt that if I got him into trouble,
I couldn't protect him. I think some of the scientists did
kind of incite the people on the other side of the Iron
Curtain, or the Bamboo Curtain to speak out, and they got their
heads chopped off. Their scientific status could only protect
them so far- -not too far. I didn't want to urge anybody to do
that. I just treated these Russians as individuals.

I think Charlie had made a real effort to establish good
relations with them. Peter Franken at the University of
Arizona did too. I gather since the breakup he's been very
active in taking money over to help support some of the Russian
scientists. He says he has travelled carrying big bags of

231

money with government permission because there's not any other
good way to send it.

Riess: We were trying to get so many of them to come to this country.

Schawlow: Well, a lot of them did, but there are a limited number of

jobs, we haven't got jobs for everybody. And I don't think we
want to destroy Russian science. I certainly have learned a
lot from Russian science and technology. For a long time they
were very good in theory, they had a lot of ideas, but they
didn't seem to have the ability to carry out the experiments as
quickly as we could.

Riess: Is that because their bureaucratic structure is even worse than
ours?

Schawlow: It is, and also they didn't have the industry. In fact, I

asked Gorbachev about that when he visited here. A number of
us were invited to sit around a table and he would answer
questionsthey [the questions] were screened ahead of time.

I asked himrecently there had been a girl from the Soviet
Union who came to Stanford for an operation. She had a large
blood tumor that was removed by a laser. From the beginning of
lasers, as soon as there was anything at all, various people
had ideas to make instruments. They'd start a little company
to make them. They hoped to make money. Some of them did,
some didn't. But it meant that all these instruments were very
quickly available to us.

I asked, "Can you do that sort of thing in the Soviet
Union?" Well, he sort of evaded that. He said, "Well, we hope
to make things available quickly." But in fact, they built a
lot more stuff at the laboratories because they did not have
the instrument industry that grew up rapidly here. They had to
have much larger support staffs and build things within the
institutes. The different ministries were insulated from each
other. I don't think that the Academy of Sciences people could
talk to the people in the Department of Machine Building, or
something like that.

The compartmentalization of Soviet science was a big
drawback, I think. If they really put the money into something
like the space program, then they'd build everything within
that organization and could do very well. But for independent
science- -they did have much larger staffs than we did, but they
didn't have all the marketplace to draw on that we had.

232

Riess: Did scientists there have the same kind of liaison with the
government that Charlie describes when he was on the science
advisory panel? Do they have that in the Soviet Union?

Schawlow: I'm not sure how they do it. They have this Academy of

Sciences which is quite different from our Academy. It's very
powerful, it runs a lot of institutes, has it's own budget,
where our academy is strictly an honorary thing- -it can do
studies, but no more. "Le'-to-khov"--or "Le-t6'-kov" because
in Russian it's "Le-to'-kov," but he says that when he comes to
the west it's "Le'-to-kov," because we tend to put the accent
on the first syllablehe mentioned meeting with Brezhnev. So
the favored scientist did have access to quite high officials,
but I don't know the details.

I know Basov became very powerful. Apparently there was
some power struggle between him and Prokhorov, and he became
head of the Lebedev Institute, which is a very large institute
for research on electronics and then lasers. After that,
Prokhorov got his own institute, the General Physics Institute,
and he had a large group. I noticed one year his name was on
more than twenty papers; I'm sure he didn't do all of those
himself, but he had a big group working. They both did some
nice things. They're both very capable people, and a lot of
the other Russian scientists are too.

Anyway, I think it was a good thing that people like
Charlie feel that they need to keep in touch with the Russians
and build bridges as much as they can. But I didn't feel it
was something I could do.

Riess: That reminds me of the state of physics in Russia at the end of
the Cold War. Have you brought Russian physicists to Stanford?

Schawlow: The department has. We have a theoretical astrophysicist,

Andre Linde, who is very distinguished, and his wife who is a
nuclear physicist. They have been added to our faculty. I
don't know, there are probably others around the place too, but
I don't know for sure. But I haven't been in a position to
find jobs for anybody.

There are a number of Russian scientists around various
places, but we have only the two. Ours is a very small
department compared to most other major physics departments.

233

People and Projects
[Interview 7: November 14, 1996] ##

Optical Science

Riess: So much of your work has been taken up by people in the field
of optical science. What do physicists think of the optical
scientists?

Schawlow: The physics community thought of optics people as being lens

grinders-- [chuckle] a lot of them were. The Optical Society is
a very diverse mixture of people, a lot of people interested in
vision, and some in color imagery. And oh my, those people
were fussy about terminology. You had to use the exact proper
terms, and they didn't always agree on which ones they were.

Mary Warga was the executive secretary of the Optical
Society. She had been a professor at University of Pittsburgh
and had worked in spectroscopy, I think analytical
spectroscopy, I'm not surethat is, analyzing compounds, or
alloys. However, she was full time with the Optical Society
and when the first lasers operated she really went after them
to get the laser people into the Optical Society. She came to
Bell Labs and visited with a number of people there.

She got Maiman to give a talk at the first meeting that
they held after his announcement --on very short notice, but she
did it. Then they had another meeting in Pittsburgh in the
following spring and a lot of invited papers on lasers. I
gather some of the old line optics people got rather annoyed at
that.

Riess: It's interesting, you say with a smile that they were lens
grinders. At the same time the question of coherent light,
must interest people in optics.

Schawlow: Well, of course they didn't have sources of coherent light
before that.

Emil Wolf at the University of Rochester has done a lot of
theoretical work on partial coherence of light. You can get
it. After all, the famous Young experiment which sends light
through two slits and has them interfere on a screen some
distance beyond that, really requires that the light reaching
the two slits be somewhat coherent. They've done that since
Young's time which was the early 1800s. Every undergraduate
physics course does it.

234

But the way we always did it was that we'd use a small
source, have a narrow slit in front of the source, have a
filter so that you'd get a narrow range of wavelengths. Then
the light reaching the second pair of slits, which was maybe
several meters away, would be only waves that are going almost
entirely in one direction. So they would have a plane
wavefront and they'd be coherent, nearly enough, across the two
slits. So you'd get partial coherence.

With the laser we had a source of coherent light which was
something quite different. And that stimulated a lot of work,
a lot of physics questions in connection with lasers. It also
suggested a lot--I didn't get into that much, but it did
suggest interesting studies of materials related to laser
material. There "d been work on that for many years in physics,
and chemistry. Again, not a forefront sort of thing, but it
interested me when I got interested in lasers. Actually the
first nine or ten years that I was at Stanford, that was really
the main focus of what we did, at least a lot of what we did.

For instance, I had found at Bell Labs that the extra
lines, so-called satellite or neighbor lines, in the spectrum
of ruby were caused by chromium ion pairs. Looking at the
crystal structure, you could see that there were a number of
different sites, that the neighbor could be in different
directions. It could be right along the symmetry axis or off
to one side in various directions.

Mollenauer, Imbusch, Emmett, McCall

Schawlow: I got Linn Mollenauer to work on trying to unravel that by

applying stress to the crystal, just putting a weight, a piston
pushing on the thing. We could see the line shifted in various
ways. The direction in which you get the maximum shift would
be along the direction of the particular pair.

Mollenauer was actually my first student and has done very
well at Bell Labs. He worked for a while as assistant
professor at Berkeley, but then he went to Bell Labs. He's
done a lot of work on optical solutions which are very good for
long-distance high speed communication over fiber optics.
They're a serious competitorthat they may be the system of
the future, although there are other competitors. But they've
shown remarkable results.

Riess: You came to Stanford planning to work on spectroscopy.

235

Schawlow: Mostly that. I don't know, there wasn't anything very

systematic. I attracted a lot of students. When I came I
attracted students really too fast. I hate to say no to
anybody.

I gave them various problems that occurred to me. We were
kind of exploring. I should mention that somebody asked me,
about the time I was coming here, how I was going to compete
with Bell Labs when they had so many good people working on
lasers. I said, "Well, it's simple. I won't compete. I'll do
something different." That may have been part of the reason
why I didn't really work on trying to find new laser materials
and instead I worked on trying to clear up some of the physics
questions that were suggested by lasers.

Riess: Did you finish talking about the chromium ion pairs?

Schawlow: That was one of the things we did. Gosh, my memory begins to
fail me. I have a time remembering exactly what each student
did now, some of them, although I can remember most of them.
Frank Imbusch was the second student.

Mollenauer and Imbusch had been working with George Pake,
but Pake was leaving- -he went to be provost at Washington
Universityso they asked to work with me. Imbusch was from
Ireland, and is back there now, at the University of Galway.
He was very good at getting things done. Mollenauer was rather
slow, but deep. He always saw things a level deeper than I had
thought about them. But Imbusch was quick for getting things
done, and so we did a number of "Oh, let's try this out" kind
of experiments.

Riess: Would it happen in the lab or would you sit around?

Schawlow: We would have meetings every week, a group meeting to discuss

things. I would talk to the students some, go around and visit
them in the lab or they'd come and see me to discuss what they
might do next. Mostly they had a lot of freedom to do pretty
much whatever they wanted to.

I guess mostly I would ask questions and sometimes make a
comment, a suggestion. I'd have these seminars, group
meetings, and have the students talk. I would ask "dumb"
questions once in a while to make sure that other students
there understood what they were saying, and perhaps even to
clarify their own thinking. I was really not ashamed to ask
stupid questions because I knew that other students in the
group were working on different things and they didn't know.

236

Then, one student came along, John Emmett, the red-headed
guy in the movie ["Science in Action"]. He had come from
Caltech and apparently had a sort of checkered reputation
there. He'd done very well at the things he was interested in,
and not bothered with other things. However he'd gotten
through all right.

He was really a strange one in some ways. Once he sort of
disappeared for some months. I didn't see him, so when he
reappeared I asked him to give a talk at our group meeting. It
turned out that he had his own machine shop at home and he was
building parts for a big laser.

He knew more about flash lamps, I think, than anybody else
in the worldthe kind of flash lamps used for pumping lasers.
In fact, Elliot Weinberg, who was our contact with the Office
of Naval Research, put in some extra money to support Emmett 's
research, and Weinberg took Emmett with him to Europe to visit
various laboratories where they were working on laser
f lashlamps .

He really liked to build things, Emmett did, and he built a
big powerful ruby laser. It was rather expensive work, even
with the Navy money it was very expensive, the things he did.
He built a high-powered ruby laser which used a rod of ruby
that was something like six inches long and three-quarters of
an inch in diameter. I think they cost about two thousand
dollars each. They're, of course, synthetic ruby.

The way he was using them they produce ultrashort pulses
that would only last a few nanoseconds. I figured these rods
would get destroyed by the high powered light flashes in maybe
a thousand flashes. I think there are about a thousand
flashes, each about two nanoseconds, so we'd get about two
thousand nanoseconds out of this $2,000.

It was costing us about a billion dollars a second to run
this thing and I told him that. He said, "Gee, boss, I realize
that I've been here a couple of years and have only done a few
microseconds of real work." I said, "I've been suspecting
something of the sort." [chuckles]

It was very hard to get Emmett to actually measure
anything. Elliot Weinberg wanted him to measure whether
flashlamps were opaque to their own radiation in the reddish
sort of region that was used particularly for pumping neodymium

Riess:

Schawlow:

237

gas lasers and neodymium YAG lasers. 1 Emmett had the apparatus,
and set it all up he could have done it better if he'd had
another laser to probe the absorption of the discharge, but he
used a short flash lamp, a very clever thing.

Weinberg came in on Saturdays to make Emmett sit down and
actually take the measurements. That's why I put Weinberg 's
name as coauthor on a paper sponsored by NASA, even though he
was working for the Office of Naval Research!

Emmett told me years later that he really didn't want to
finish anything. He was afraid if he finished anything I'd
make him leave, and he was just having too much fun there.

It makes me think of George Devlin, another clever scientist
you worked with. Is that a question: whether or not it is
important to make them into well-rounded physicists or whether
that's even within their capacity?

Well, you try and get them to do what they can do.
them as well-rounded as you can.

You make

Emmett, after he left us, went to the Naval Research Lab in
Washington and worked on high powered lasers for a while. Then
when Livermore was starting to get into big lasers for nuclear
fusion he went there and eventually became the associate
director in charge of all their laser programs at Livermore.
After some years he left there and started a business which I
gather he sold and made a lot of money and is doing various
consulting. A very clever guy, but it was sort of like having
a tiger by the tail, a nice tiger, but-- [chuckle] --a tiger.
You really couldn't control him.

I wanted to explore various things. I got interested in
the far infrared region which was still a big hole that hadn't
been bridged really. We jumped from the microwave right to the
visible and near visible. I had one student build a big far
infrared spectrometer and I actually bought a gas laser using
cyanide gas.

1 [from Interview 5] I probably ought to admit it, that was one of my
big mistakes. Professor Dieke at Johns Hopkins had been working on spectra
of rare earth ions and crystals, and he told me that I ought to try
neodymium. I looked at the spectrum and thought, "Oh, that's awfully
complicated, that doesn't look very promising." But other people did, and
neodymium is still one of the best ions to use. You can't put it in
sapphire, but you can in a lot of crystalsand in glass, too. But I
didn't try it and others discovered that independently. [Schawlow]

Riess:

Schawlow:

Riess:

Schawlow:

238

That's a funny story. It turned out what they were using
was methyl cyanide which is a liquid, and as such is not too
poisonous. But if you're going to vaporize it as you would in
gas lasers, you have to have good ventilation, which we did.

But it turned out that Emmett had been using acetonitrile
as a liquid to measure the energy of his laser pulses. He put
it in a flask with a tube coming up that measured the expansion
when a laser pulse struck it. It turned out that acetonitrile
was methyl cyanideit's the same stuff.

We thought originally that this laserthe people who
invented it thought it used the CN radical, and that would have
a magnetic moment, so it could perhaps be tuned by applying a
magnetic field. But by the time we really got under way, other
studies had shown that it wasn't that, it was the HCN which was
produced somehow in the discharge, another really nasty gas,
but that is not a free radical and wouldn't be magnetically
tunable. So nothing much came of that. We did some work on
tuning the thing as much as you could by going to different
transitions.

Bruce McCall was a student who worked with that, and McCall
was an unusual one. He started out with me. He came from a
fairly wealthy family, of auto parts manufacturers in the
Detroit area. He was wrestling with the question of whether he
should go instead to the business school. He was admitted to
Harvard Business School and he went there and got an MBA, but
he came back. He finished working on this cyanide laser.

He later started his own company, Molectron, which wasn't
terribly successful, except that he eventually sold it at a
good price because they had begun to develop a device for using
lasers for treating stomach ulcers. Cooper Laboratories was
sort of collecting laser medical companies, so they bought this
at a good price.

This was still in the sixties or was this in the seventies?
It was probably in the seventies when they had this company.

Seems like something people might have been tempted to do a lot
of, grabbing at something, turning it into a company, and into
a profit.

Yes, but I don't think that was his intention. He did make
infrared detectors, and the detector part was spun off by
Cooper Labs. There is now still a Molectron detector company,
but he has nothing to do with it. They made lasers of various
kinds, but they didn't sell very many of them, I don't think.

239

And it was sort of just scraping along until they started on
this medical thing, and that was salable.

Riess: When you have an idea, like the methyl cyanide, do you have to
know where you're going to go with it?

Schawlow: Emmett was using it just as a liquid that had a fairly low heat
capacity and would expand when the laser pulse hit it, just as
a kind of thermometer. But when we bought that cyanide laser,
I thought that it worked with the CN radical and that it could
be tuned by magnetic field. That turned out to be wrong, so we
just did a little more exploring of its properties and closed
that off.

Titanium in Ruby Rods

Schawlow: We built a far infrared spectrometer. We used that for

studying crystals, looking for lines from ions in crystals. It
was related to the work that we'd been doing in the visible
region. Some of these ruby lines were separated by intervals
that would correspond to transitions in the far infrared
region. We tried to see whether they really were from the same
pair of ions or from different pairs, whether they just
accidentally happened to be near each other.

In fact, we had originally reported that they were from
the same one, but we were beginning to doubt that. And we did
get a big rod of dark ruby, about six inches long, and looked
through it, and the particular line we were concerned about was
not there. So we looked at crystals with other transition
metal ions, trying to see if it was an impurity, things in the
iron series, like titanium. Well, we got a crystal of titanium
and there was that line.

A few years later we had a visit from a man named Otto
Deutschbein. Deutschbein must have been German originally. He
had written his Ph.D. thesis in the early thirties. He had
done a lot of work on the spectrum of ruby and other crystals
related to it with these transition metal ions. We told him
about this, that this line turns out to be titanium rather than
chromium. And he said, "That's interesting." By that time, he
was at the French Post Office, which is the big communications
lab in France.

He said, "You know, it's interesting. Djevahirdjian in
Switzerland has made a lot of ruby rods that are used in lasers
in Europe." He had sent samples of his rods to the laboratory

240

at the French Post Office, and they had found titanium in them
and they reported that to Djevahirdjian, and he said, "Oh,
goodness! Don't tell anybody. That's my secret." The
titanium helps the crystals grow better into the large
crystals.

Riess: You might decide to just go through every material and come up
with similar kinds of data about it.

Schawlow: It would have been better, actually. We had crystals of

titanium-doped sapphire, and this turns out to be a very good
laser material. Well, we didn't even try it as a laser
material.

Riess: So that wouldn't be an approach?

Schawlow: It could have been, but we didn't. I don't know, I was very
opportunistic, I just sort of tried various things. I really
wasn't well focused, didn't plan, wasn't systematic. I just
tried whatever happened to look interesting at the time.

Riess: There is something about the process here that makes me

curious. Whenever you have an idea, you need to get money for
it, and you need to write a proposal?

Schawlow: No. I would only work with the things that were vague enough
that I could have a good bit of latitude to do what I wanted.
Even when I did propose something fairly definite, if I did
something different they would accept it in those days. So I
just didn't write special proposals for each project. I never
really had enough money, but I managed to scrape by on what we
had. I had very few postdocs because I really felt I couldn't
afford them. But we had some.

We did do some things on rare earth ions in crystals. In
fact, I had a student working on crystals with praseodymium and
lanthanum fluoride. I was consulting with Varian Associates,
and they had somebody there who liked to grow crystals of
lanthanum fluoride. He gave us some samples with various rare
earth materials in them and we did various things with them.

Many years later, I had another student who was doing some
work with that, which was suggested not by me but by a postdoc,
Steve Rand. And I went to look up some information about this
crystal and I was rather surprised to find that my name was on
a paper back around 1963 about this very crystal. The work had
been done though mostly by Bill Yen, who was a postdoc, and by
that time was a professor--f irst at Wisconsin and then the
University of Georgia.

241

Riess: Yes, he's a contributor to this book dedicated to you, isn't

he? It says he joined the Schawlow group in the summer of 1962
as a research associate, "increasing the size of the team to
four." 1 The four would have been Imbusch, Mollenauer .

Schawlow: Somewhere around there I got Warren Moos from Michigan.

These people sort of were offered to me. At that time, I
was still just kind of drawing on the money that was available
in the microwave lab, not really worrying about budgets yet.
Then I began to get my own contracts and had to worry about
budgets .

Light-Controlled Chemical Reactions ft

Schawlow: There are two things I should mention. As you've probably

learned from Charlie Townes, one of the things that stimulated
my interest in how to get sources of shorter wavelengths, and
also brought me to Columbia, was the Carbide and Carbon
Chemical Fellowship, which had been started by Helmut Schulz.

Schulz had a vague idea that you could control chemical
reactions by light of some wavelength between far infrared and
visible. That was really the only application that we had
vaguely in mind when we were working on the idea of a laser.
So I thought I would like to do something on that.

I got one student, Bill Tiffany, to try and study a
reaction that might be stimulated by a ruby laser, which was
essentially the only laser that we had, really, in those days.
We tried looking at reactions in bromine with ethylene, I
think. We found that you could tune this laser by changing its
temperature. As you scan across the spectrum, a lot of lines
are drawn in the bromine, but when you're on a line you could
get a reaction. If you're off a line, you wouldn't get a
reaction. So it could be isotope-selective.

In the end we didn't get any separation. There were fast
chain reactions that scrambled the isotopes before we could
extract them. Actually, chemists knew about that sort of
thing, but we didn't. So in the end, we did initiate the
action selectively, but we couldn't complete it.

1 Lasers, Spectroscopy and New Ideas, A Tribute to Arthur L. Schawlow,
Editors, W.M. Yen and M.D. Levenson, Springer Series in Optical Sciences,
Volume 54, Springer-Verlag, 1987.

242
Riess: Did you consult with chemists?

Schawlow: Only to get the samples analyzed. I don't think there was
anybody there [in the chemistry department] who was
particularly interested in this sort of thing at the time.
They did use a mass spectrograph to analyze what we were
getting.

However, after Bill Tiffany finished, I couldn't find other
students that wanted to work on chemistryit wasn't physics,
it was chemistry. I also began to have qualms. It would be
okay to separate bromine isotopes, but if anybody found an easy
way to separate uranium isotopes that would be a real disaster.
So I decided I just wouldn't work on isotope separation of any
kind, because I might have a good idea that made it easy, and
that would be terrible.

Riess: You never published?

Schawlow: We published what did on the bromine, but we didn't do anything
further. What I know now is that you really have to do those
things fast. There's a lot of work done on laser isotope
separation. Indeed, if they ever need to separate more uranium
isotopes they would probably build a plant using lasers to
separate it, rather than the diffusion or mass spectrographs
that they used before. Livermore did a lot of work in that
later. There was some done at Hanford, too.

It's okay for the government in their big secret labs to
work on that sort of thing- -anyway, I thought it best that I
just not touch it. The way they do it is not easy. It's quite
difficult. On the other hand, Dick Zare has done work
separating chlorine isotopes. That's apparently very easy. If
it were as easy to do in a garage, if it were that easy to
separate uranium isotopes, that would be a disaster.

Riess: These issues and concerns make me thing about the Pugwash
conferences. Did you attend them?

Schawlow: No, I never did. Never got involved, never got invited. I
think we talked before about how I really kept out of
government stuff, largely by refusing secrecy. I think, also,
I was spending an awful lot of time with Artie and with my
classes and my students and so on. I just didn't have any
energy left over to do those things. Probably I didn't get
invited because I wasn't involved with the government. If I'd
been asked, it would have been hard to refuse. But fortunately
I wasn't asked.

243
Consultancy at Varian

Riess: Also, consulting with Varian. Was that ongoing?

Schawlow: No, I gave it up after a while. I had become a director of

Optics Technology, which was a struggling little company run by
a man named Narinder Kapany. He was a Sikh who had gotten a
Ph.D. at Imperial College, London. He was a man with a lot of
ideas, but it was a badly run company I'm afraid, which I
couldn't do much about. They had a lot of clever ideas, and
every year he'd have a different product which had a different
market. So they lost money and eventually went bankrupt.

But he wanted me to consult with them full-time at a time
when things were prosperous. And I felt the Varian thing
wasn't getting anywhere. They didn't have a real commitment to
basic research. Several times they decided they were going to
make gas lasers, and then decided they weren't, so I didn't
feel that was really very interesting.

Riess: What do you do, as a consultant?

Schawlow: You just go over there and they tell you what they're doing.
Maybe they ask some questions. Maybe you can answer them,
maybe not.

Riess: You might have a number of consultancies?

Schawlow: Could have, as long as they didn't conflict. At one point,

Hewlett-Packard wanted to start making microwave spectrographs
and wanted me to consult. I felt that that wasn't fair because
that might compete with something that Varian was doing. I
mean, they're both in the instrument business. So I didn't
take that one. But I could have done things that were not
competing.

Riess: When you're on a board of a small scientific company, don't you
end up being a scientist on that board?

Schawlow: Sometimes, yes. Sometimes you make technical comments and
sometimes you come in and talk with people in the lab
occasionally. But in principle, the board has to set policy.
Kapany was a strong leader and I really don't think I did much
good. I think I sort of wasted my time. Ended up making no
money at all.

Riess: Did Stanford make policy about how physicists were or were not
to be involved with the larger community?

244

Schawlow: The had some policy, I think largely driven by the engineering
department where they had some professors that were running
companies at the same time. I think they had a rule that you
couldn't spend more than one day a week on the average
consulting. I spent a good deal less than that.

I'm afraid that I don't think I really did anybody much
good with my consult ing- -maybe helping them avoid making some
mistakes. I don't know, their problems just didn't really turn
me on very much.

The Hodgepodge of Projects, Ray Guns, Full House in The Lab

Riess: You were very engaged in what you were doing in those years,
the sixties, at Stanford?

Schawlow: Yes, I was enjoying it, it was interesting. I didn't think the
individual projects were terribly exciting to people in other
branches of physics.

Much of our work was exploring the spectroscopic properties
of transparent crystals containing rare earth ions. Many of
the lasers existing then used these crystals, among them ruby.
The spectra are the raw materials from which you may be able to
make lasers or other devices. We didn't have widely tunable
lasers yet, and so we worked mostly with high- resolution
grating spectrographs.

Sometime in the late sixties, Roger MacFarlane joined us.
He had obtained his Ph.D. in New Zealand, and knew much more
than I did about the theory of these spectra. He was also a
good experimentalist, too. After about two years with us, he
went to the IBM research laboratory in San Jose, California and
is still there. He has done very nice things through the
years, and collaborated with us in the 1990s when we once again
turned our attention to ions in solids.

One thing that did happen in our lab- -I wasn't really the
initiator, it was a man named Robert White, an assistant
professor, who suggested that they look at manganese fluoride.
Manganese fluoride is an anti-ferromagnetic material at low
temperatures. That means that instead of all the electron
spins being lined up parallel as they are in a ferromagnet,
they are lined up anti-parallel. But there could be spin waves
in this thing. White suggested that students look for spin
wave side bands, and indeed, they found them. That was quite a
nice thing and it surprised a lot of people.

245

Somehow, I felt that what we were doing was kind of a
hodgepodge of stuff in the sixtiesbut each one was fun. I
did get invited to give the Richtmyer Lecture at the joint
meeting of the American Association of Physics Teachers and the
American Physical Society in 1970, I think. I chose for that a
title, "Is Spectroscopy Dead?" Laser spectroscopy hadn't
really begun yet.

I remember asking various people what they thought--! asked
colleagues if they had ideas. Felix Bloch came right to the
point. He said, "What do you mean by dead?" I said, "Oh,
turned over to chemists." [laughter] That had happened to
microwave spectroscopy. No physicists were working on
microwave spectroscopy after our book came out, I think. That
pretty much killed it. Everybody thought, "Well, it's all
done. All the physics is done." But the chemists were more
interested in looking at a lot of different molecules with
microwave spectroscopy.

Riess: Chemists, or physicists who are interested in chemistry?

Schawlow: Usually they were chemists who were interested in the physics
of things.

So, anyway, this was a great honor. I didn't give a very
good talk, and I never did get the manuscript written up, which
I was supposed to do. I had the flu- -I got the flu when I went
to this meeting in Chicago. It turned out that Luis Alvarez
had been president of the American Physical Society, and he was
supposed to give his retiring presidential address. But he had
the flu so bad that he couldn't give his address, so I was
allowed to ramble on a little beyond my allotted time, [laughs]
But I had the flu and I was not feeling well at all.

They said that Alvarez was there and was being attended by
his famous father you know, Walter Alvarez, a very famous
doctor at the Mayo Clinic. Although what we had done was
rather hodgepodge, people thought it added up to something.

[looking through a list of his publications] We were
starting work on measuring the position and width of the
spectral lineswith Imbusch, again, and some people at Bell
Labs. I guess that was after Imbusch had gone to Bell Labs.
He was there for a couple of years.

Riess: I imagine that all of this writing of papers took a huge amount
of time.

Schawlow: It does, but in many cases a student or a postdoc would do some
of the work.

Riess:
Schawlow:

246

I see there's one here about a portable demonstration laser
that I wrote. Ken Sherwin had made my ruby ray gun and I was
getting a lot of inquiries from high school kids who wanted to
make a laser. I offered it to Popular Science, and just about
the time I got the answer back, 1 got a letter from some woman
in San Jose complaining I was giving dangerous toys to
children. Of course, this was a toy housing I'd used, it
wasn't at all a toy.

Then they [Popular Science] wrote me and said they had
another article about making a laser, but they would buy my
article for two hundred dollars and not publish it. I thought,
"Well, maybe it's better not to publish that." They were
offering, however, to send more detailed instructions on how to
build a ruby laser. I gather that those instructions changed
over the next few months so it became more and more what we had
in our paper! [laughs]

Then I had the cute experiment about measuring the
wavelength of light with a ruler, where you just have a laser
beam skimming along the surface of the laser, being diffracted
from the rulings at an almost glancing angle.

Where did you publish that?

That was in the American Journal of Physics, which is the
journal of the American Association of Physics Teachers.

So that might be useful as a demonstration.

Oh yes. I think a lot of people have used that.

[looking through papers] Oh yes, we studied strontium
titanate, which is a ferroelectric material, with chromium as
an impurity. We tried to see if we could change the intensity
of the fluorescence by putting on an electric field. We
eventually got a small effect. (That was done with Stan
Stokowski. )

The idea was that you deform the crystal enoughsee, the
chromium ion, if it were at a perfectly cubic surrounding, it
wouldn't be able to have any electric dipole emission at all.
But because it's not at a center of symmetry, it has an
electric field which deforms the ion and makes it possible for
it to emit. So the idea was to apply an external electric
field to deform this rather deformable material, strontium
titanate, and see if that would change the intensity. We did
succeed in that.

247

Let's finish this [review of the students and postdocs]
off. You know, we had all the students I could handle. At one
point, I had ten students and I told them I'd never given a
Ph.D. Well, after that they started coming out the pipeline.
But in 1968 I think, I had some contact with Dick S lusher who
was getting his Ph.D. at Berkeley with Erwin Hahn. He had a
National Science Foundation postdoctoral fellowship. He wanted
to come, and it wouldn't have cost me anything, but I talked
him out of it. I was feeling rather despondent at that time.
We didn't have any room, we didn't have any money to spare.

Riess: Here?

Schawlow: Yes.

Riess: You had your ten rooms?

Schawlow: Yes, but they were all full of students. Especially, we didn't
have any money to start anything new. I suggested that if he
wanted he could come, but maybe it wasn't too good an idea. So
he went to Bell Labs instead and did very well.

He got the Schawlow Prize from the American Physical
Society Laser Science Group a year ago, and I was there to tell
the story of how I foolishly missed a chance to have him work
with me. But I was just, well, feeling kind of depressed and
not having any thrilling ideas, and really not having much
freedom to do new things .

Riess: That's the part I don't understand, not having the freedom.

Schawlow: I didn't have the money, really, to start something that would
require a lot of new equipment. I had good spectrographs of
several different kinds, but--.

Riess: But this is the drying up of money time or what?

Schawlow: Yes. It was around that time that NASA decided they couldn't
continue to support this work. They were under pressure to do
things that were more closely related to their missions. So
they said they were not going to be able to support me any
longer. The Army Research Office had been giving me small
amounts, $30,000 a year. It was a little later that they
dropped out .

At any rate, I felt, "Well, I could go on doing the same
sort of thing, but I couldn't really start anything very
different." So I didn't encourage him to come although I would
have taken him if he decided he really wanted to.

248

Fortunate Conjunction

Traveling

Schawlow: Then there's something, and I don't know whether I ought to say
it or not, but I was on the Physics Advisory Panel of the
National Science Foundation. They started a new program,
offering equipment grants. And the next year's meeting, Wayne
Gruner, head of the physics section, said, "Well, we haven't
been getting many applications for those grants." I said,
"Well you've got mine." He said, "Oh really? Do we?" And
not very long after that I got the grant. That was a very
fortuitous timing, because it came just about the time that Ted
Hansch came here.

Now, again, I was not really too interested in taking him
on, but I got this letter from Peter Toschek, whom I had met.
He wanted to know if I could take this man as a postdoc. I
wrote back and said that I didn't have any money and he said,
"Well, would you take him if he'd get a NATO fellowship?" I
said, "Oh, all right." He did get that, and when he arrived,
it was a very small fellowship. When we saw how good he was,
we found another hundred dollars a month or so to help him.

Riess: You had met him before, hadn't you?

Schawlow: Well, he told me that, but I didn't remember that I had met him
at a conference in Edinburgh. But I'm very bad about that sort
of thing.

Riess: As a side note, it seems to me one of the pleasures of being a
physicist was the far-flung conferences. Because of your
responsibilities to Artie, did you miss out on that?

Schawlow: Well, not really. We felt we could go away for a week or two.
By that time, Artie was living away from home. We went away
for sabbatical in 1970, and that was bad, because while we were
away the people in the house he was living in decided that they
couldn't handle him any more. There were young girls, high
school age or so, there who were afraid of him. He was big and
strong, and he was having tantrums, though he wasn't hitting
anybody. That was bad. If we'd been here, maybe we could have
soothed them. But we had to find another place for him.

Riess: Where did you go on that sabbatical and what did you do?

249

Schawlow: We went to London and I actually was ant i- commit ing to Redding.
My good friend George Series was there. I didn't really work
on anything much; I think I did a little study of possibilities
for x-ray lasers, but I didn't really reach any very valuable
conclusions.

I think I foolishlywhen you go to a country like that, if
people know you're there they invite you to give a lot of
talks. Doesn't seem like an awful lot for each one, but in the
end it was too much.

Riess: Too much to get any physics done.

Schawlow: Yes. That's right.

Riess: That must have been when you met Ted Hansch.

Schawlow: It may have been a year or two earlier, I'm not sure.

I remember very wellwe flew to London and rented a car,
which was a tiny Fiat, and drove up to Edinburgh. That was a
nice adventure. With that car you really sort of had to stop
every hour because it wasn't very comfortable. I think it was
a deal that Pan Am had the car rental was included in the
excursion fare.

Riess: Did you have your daughters with you?

Schawlow: Not on that occasion, that was just a week or two. When we

went to the sabbatical, yes indeed. They went to the American
School in London. One of them, Edie, the younger one, was
involved in two amusing stories there. She told someone, I
don't know if it was another student or a teacher, that her
father had invented the laser. The teacher said, "Oh, I didn't
think so. Got to ask the science teacher."

The science teacher said, "Oh no. The laser was invented
by a Mr. Laser, I think it was Samuel Laser." She was sort of
crushed, but I managed to find a magazine or book that had the
facts, [laughter]

She was eleven at the time. They had a long weekend for
the American Thanksgiving, so we all went to Paris. She
complained later, everybody else had a holiday but she had to
go to Paris. In later years she thought that was funny.

[tape interruption]

250

Ted Hansch and Edible and Tunable Lasers

Riess: Ted Hansch came to Stanford In May, 1970?

Schawlow: Yes, he came before I went on my sabbatical and he did some
wonderful things, including when I was away. He was very
generous about putting my name on things when he'd really done
most of it. He was just a genuinely nice person, good sense of
humor, as well as being a wonderful physicist. He had good
hands and could build things himself very quickly- -which I
could never do. Also, he was good at theory.

Riess: Did he arrive with something that he was working on?

Schawlow: He had worked on gas lasers for his Ph.D. thesis, but he was
willing to work on anything that looked interesting here. I
can't remember the exact sequence, but I think we got that
equipment grant just before he arrived, and he helped us decide
what it was we were going to buy and I decided to buy two
lasersyou could then get them commercially. One was a
nitrogen laser which gave short pulses, but they were a hundred
kilowatts, a hundred thousand watts. They could pump all sorts
of dyesdye lasers had been discovered, but they hadn't been
used for much.

One of the first things Ted did was to find a way to make
this dye laser fairly monochromatic. One of the advantages of
dye lasers was that they were tunable, but their output tended
to cover a rather broad wavelength band. Whereas for
spectroscopy you want them to be fairly monochromatic so you
could tune them across spectral lines and see fine details.
He was able to make a pulsed laser that was fairly
monochromatic, and it was pumped by this nitrogen laser.

This nitrogen laser also was used we had some fun playing
with various dyes because almost any dye that glowed would
lase, and even the gelatin filters, the photographic filters,
would lase. So then 1 had one of the most fun experiments 1
did, about the last time I did anything with my own hands. I
decided, well, if you can put dyes in gelatin, maybe ordinary
Jello would lase. And it didn't. I tried all twelve flavors
of Jello and they didn't fluoresce very well. I guess people
don't like fluorescent foods, [laughing] Many of the dyes that
fluoresce are poisonous anyway.

But I realized there was a dye that wasn't poisonous,
namely fluorescein, because dentists paint that on your teeth
to show up the plaque. So I put some fluorescein in some Knox
gelatin and managed to get laser action in that. So we

251

published this and put in a phrase that this is the world's
first edible laser material. [chuckles] That's often been
quoted.

Riess: That's more comic strip material.

Schawlow: It is, but it turned out to be something very useful that we
didn't realize. Even before we publishedwe weren't
secretive, but somehow somebody at Bell Labs heard about this,
maybe had a preprint, and they realized that photographic
plates used gelatin and it could diffuse dyes into the
photographic plates, so they could put patterns on there, like
diffraction gratings, and could tune the laser with the pattern
of lines on the photographic plate. Lines one behind the other
would act as a grating, depending on the spacing of them. So
they published that.

And then people with semiconductors began to put gratings
of that kind in their semiconductor lasers to help tune them.
Something quite serious came out of this fun experiment with
the edible laser. You never know what will come from research.

Hansch had this tunable pulsed laser, and I said to him,
"If you want to get the interest of physicists, then you should
work on the hydrogen atom." That's about all I did on it, but
he then made a discharge tubeyou could flow water through it
and have a discharge which would produce hydrogen atoms, and
observe the fine details of the hydrogen spectrum. That was a
little later. I guess that was '71, probably after I came back
from my sabbatical.

Riess: This work shed new light in some basic areas? Is that what you
mean about getting the interest of physicists?

Schawlow: Well, yes, the theory of hydrogen atom the details are based
on the theory of quantum electrodynamics which includes
detailed interaction of the atom with the electromagnetic
field. That theory is a very good one. Now Hansch has gone
on, and others have too, to make really precise measurements on
the hydrogen atom, and so far quantum electrodynamics is still
okay. They haven't found anything wrong with it.

Schawlow: From these first experiments he was able to measure the

wavelength of the hydrogen atom line by a factor of ten or so,
more precisely than could have been done before. The hydrogen
atom line is very broad ordinarily, broadened by the Doppler
motion. Hydrogen is a very light atom, so the atoms are moving
rather fast, and that made the spectral lines kind of broad.

Riess:
Schawlow:

252

And they knew from radio frequency experiments what hidden
structure lies within this broad line, they don't know the
relative intensity components. To find the center of the line
of the components was hard, but he was able to resolve it very
completely and could make a more accurate measurements of the
absolute wavelength. He has gone on far beyond that in his
work in Germany. 1

I think one of the reasons he left us was thathe wanted
to continue to refine these measurements on hydrogen, and it
was just so expensive that we simply could not get enough money
for it from American sources. I gather we had one of the
largest grants in the atomic field, but grants in atomic
physics are generally not anywhere near as big as in nuclear
physics. We really couldn't afford to do the things they've
been able to do in Germany.

How long did he stay here?

He stayed with us about fifteen years. We made him an
associate professor after two years of post-doc--he wasn't
willing to take assistant professorand then about a year or
so later we had to give him tenure because other places like
Harvard and Yale were trying to get him. He became a full
professor quite young, because he was so in demand. We kept
fighting off German offers, but eventually we couldn't. There
were several things : Germany is home although his English is
wonderful, he had a talent for languages as well as everything
and it was only every couple of years that I might find a
slight error in idioms or something like that. But they speak
German in Germany, and they also have very good facilities.

Doppler-free Spectroscopy

Riess: And for your work it made a long-term difference to have Ted
Hansch there?

Schawlow: Oh yes. Yes. We switched directions entirely. We pretty much
stopped working on solids and could do studies on gases.

Ted had found a way to get rid of the Doppler broadening by
using two beams going in opposite directions from the same
laser, separated by a beam splitter. The only atoms that would

'Ted Hansch is now a professor at the University of Munich and
director of the Max Planck Institute for Quantum Optics.

Riess:
Schawlow:

253

interact with both of those would be atoms that were standing
still, because otherwise they'd be Doppler-shifted differently
for the two beams.

He applied that first to iodine vapor because he could use
a krypton laser that we had bought. Iodine has lots of lines
at all wavelengths so it was easy to get detailed spectra.
Marc Levenson was a student who worked with him on that and he
was maybe the best physicist I had of all my students. He did
a very good job on that and then several other things, too.

So he had this method of Doppler-free spectroscopy which he
then applied to the hydrogen with a pulsed dye laser. The
argon or krypton lasers wouldn't tune very far, just within the
width of the line. But as I say, well, the old saying: "If you
can't get the mountain to come to Mohammed, well, take Mohammed
to the mountain." [laughs] If you can't tune the laser to the
line, well you get something that has lines everywhere.

That began to get me a little interested in molecular
spectroscopy. For years I'd been telling people that a
diatomic molecule is defined as a molecule with one atom too
many [laughter] --if you get the second atom then things get
much more complicated. You have vibration and rotation. Then
I started thinking of ways you could selectively label a
particular state, by saturating it. We began to do that and we
found several different ways of doing that, using lasers to
label states of molecules.

Label?

Label them, yes.

What we do is use one laser tuned to just one line in the
spectrum and you chop this laser off and on. When it's on, it
would saturate this line; that is, it would pump atoms out of
the lower state so that there are fewer there, and all the
absorption lines coming from that particular lower level would
be weakened. So if you scan through it, you'd see those lines
being modulated. They'd be alternately weakened and restored.
Or you couldlater on, we used pulsed lasers and did a two-
step excitation. The first laser would put atoms into an upper
level and then a second laser would go on up from there. So
again, you'd have labelled this one particular level.

We were able to simplify a lot of spectra. We worked
mostly on the sodium two, Na 2 molecule, which was complicated
enough. Sodium is easy to vaporize, and it came at a
reasonable wavelength for lasers in the visible, the yellow to
orange red section of the visible. So we found a lot of new

254

levels that hadn't been recognized before. And although I
really wasn't too interested in molecular spectra as such, I
was interested in this technique of simplifying spectra.

Riess: What is the appeal? The simplification in itself?

Schawlow: Yes, it is. I'd always thought molecular spectra were just too
horribly complicated for anybody, although people somehow did
analyze them. The thought of making them more tractable,
although the procedure is tedious, still, it was powerful and
that was an appeal for me. So 1 had several students working
on various aspects of that.

Brillouin Scattering: Marc Levenson

Schawlow: We did a little bit of work on the Brillouin scattering. When
I had that equipment grant, I bought a krypton laser. It was a
fairly expensive thing. The krypton laser appealed to me, if I
was only going to buy one. It had a wide range of wavelengths.
They could tune it to just a few lines here and there, but they
pretty much covered the whole visible spectrum.

So we got this thing and people started asking, "Well, what
are you going to do with it?" I thought, "Well, maybe I can
look at the light scattering in bromine," which is a pretty
opaque liquid in the visible. But this laser had one line out
at 7900 angstroms which is really in the near infrared.

I asked Marc Levenson to do that and he did a great job.
He not only stabilized the laser by putting a Fabry-Perot
etalon in the thing, I think temperature controlled, so he made
the laser quite narrow band, but then he built a scanning
Fabry-Perot to scan the spectrum. He did get the Brillouin
scattering. He could measure the velocity of sound at ultra
sonic frequencies in the liquid.

But he noticed the shape of the curves from the
interferometer were not quite right. There was a broad
background which should have dropped nearly to zero. It had a
background in between the peaks. He suspected that there was
something else going on, so he looked at the spectrum with one
of our spectrometers and found that there was indeed a broad
background going out several hundred angstroms. He realized
that this was due to hindered rotation of the molecules--they
were interfering with each other in the liquidand he

Riess:

Schawlow:

Riess:
Schawlow:

255

published that about the same time as someone else discovered
that too. But it was something quite unexpected.

Levenson really was very good. He'd really think for
himself. He did most of his thesis extending the work on
iodine that Hansch and he had started, on the iodine vapor. He
measured how the splittings in hyperfine structure depended on
the what particular vibrational state you were looking at, and
found that the states near dissociation had a different
magnetic splitting. A lot of sophisticated sort of stuff, but
interesting and really quite exploratory.

Did any Nobel Prizes come out of this work?

No, I don't think so, although my Nobel Prize was given for
contributions to the development of laser spectroscopy, so
maybe it was some of this stuff, or may be the hydrogen work
with Hansch. They of course knew that I had played a part in
the transition from maser to laser.

Did Hansch come up for a Nobel Prize?

He doesn't have one yet. One of the problems, of course, was
that a lot of the stuff that he did was done with me, and there
were a lot of other people working on laser spectroscopy too.

R.R. Donnelley Co. Project in Switzerland

Schawlow: In 1974, I was asked by people from the R.R. Donnelley Company
to consult on a project they were starting with a Swiss laser
company. The aim was to see if they could develop a system
using a large, rapidly pulsed laser to drill the holes in the
copper plating of cylinders for gravure printing. The work was
carried out at the plant of LASAG in Thun, with the
collaboration of the laser group at the University of Berne.
They had previously developed an automated machine for laser
drilling of the holes in ruby watch bearings.

For this project, I visited the beautiful little town of
Thun several times a year, along with several Donnelley
representatives. Although rather far removed from my previous
experience, the problems were fascinating and I learned a lot
about laser machining.

At first some promising results were achieved, but
eventually the task proved too difficult for the available
lasers. Also, the Swiss franc rose sharply against the

256

American dollar, making the work too expensive to continue.
Although the agreement called for transfer of any technology to
the Donnelley Company, it became apparent that there was really
nobody who could make use of it. The chairman, Charles W.
Lake, realized this and decided that their basic technology
needed to be strengthened. To do that, he formed a technical
advisory committee to meet several times a year. I was asked
to serve on it, along with some very good people including Tom
Everhart who later became president of the California Institute
of Technology.

At the meetings, some of their people would talk about
particular projects, and we would ask questions, some of which
must have seemed dumb to the experts. Mr. Lake, a truly
brilliant engineer and manager, rarely asked the committee for
advice but rather listened and then made his decisions. I
think the meetings of the committee helped to clarify the
thinking of those who made the presentations. Also, it helped
the company to recruit some excellent young engineers. By the
time that the committee was disbanded by later management
around the end of the 1980s, they had a considerably broader
technical staff.

Cooling With Laser Light and Other Good Ideas

Schawlow: In late 1974, we had the idea that you could cool atoms by
using laser light, cool them down to very, very low
temperatures and therefore narrow the spectral lines. We wrote
a short paper that was published in Optics Communication in
1975. We didn't do anything experimentally because we were
interested in hydrogen particularlythat has the widest lines
because it's so light. There wasn't, and still isn't, really a
suitable laser for cooling hydrogen. So we just published this
note, and I didn't even think to mention it in my Nobel
lecture, but it has become a rather important field of physics
since then.

Steven Chu, who's now my colleague at Stanford, did the
first experiments. Well, Letokhov in Russia, and I think John
Hall at the Joint Institute for Laboratory Astrophysics at
Boulder, did experiments on one-dimensional cooling of beams.
But Chu did what we'd been talking about, three-dimensional
cooling. He added some clever things to that that I hadn't
thought of. One wasapparently he didn't know about our paper
until after he had finished his work. He had the idea
independently .

257
Rless: He was at Bell Labs then.

Schawlow: Yes, he was and he's a very bright guy too. So he had the

idea--. We had calculated how long it would take to cool an
atom, say, of sodium, because they can only absorb one photon
every 10" 8 seconds, which is a short time. Each time they would
scatter a photon, they would only lose about one centimeter per
second of velocity. And they start out with about three
hundred thousand centimeters per second, the average thermal
velocity. So it would take a while and they're moving fairly
fast, so I thought you'd have to build an apparatus about a
meter in every dimension to cool these things down.

But he instead used an argon laser to vaporize a little
pulse of sodium vapor from a solid surface, and then just let
the faster atoms escape, and the slower ones that remained he
could then cool down to the very low temperatures. He started
this field of optical cooling, and also of trapping atoms,
which has become a big thing. This is one thing where we each
came to the same conclusion about the same time, so 1 try to
make the point that Hansch really did come up with the idea of
laser cooling independently.

(Steve Chu did win a Nobel Prize in physics this year
[1997], sharing it with two other very good physicists who had
made important advances in laser cooling. As soon as 1 could,
I congratulated him, even though I had to tell him that he had
spoiled my perfect record of never succeeding in nominating
anyone for that prize. Of course many others probably
nominated him, too.)

Riess: When Hansch came, did you expand?

Schawlow: No, I didn't. But I gradually gave up space and funding to

him, I really let him take over things more and more. I tended
to do [my work] with equipment that he wasn't using anymore. I
really gave him priority over everything. I'd kind of make do
with things that I could scrounge. I didn't spend very much on
myself.

Riess: Why did you behave that way?

Schawlow: Well, he just was so good and I didn't really want to get in
his way.

I did some other things that were quite different. We did
this work on the molecules which wasn't thrilling, but it was
interesting. Later, the last few years before I retired, I
thought, "Well, I'll do something--! 've done enough that if it
doesn't pan out, then it doesn't really matter to me so much."

258

I got some students to work on looking for very weak absorption
lines in rare earth metals. Those things are almost opaque, but
still, the rare earth ions act like they're almost independent
from a number of studies, from neutron scattering and so on.

I had some very good students, Mike Jones and Dave Shortt,
and they built a spectrograph that was very, very sensitive and
could detect very small absorptions. They never did find any
in a pure metal, but they found some metallic compoundsthat
behave metallically. We found lines even in one that was a
superconductor. Neodymium cerium copper oxide. We were able
to look at it both above and below the superconducting
transition. It has a transition at thirty degrees Kelvin or
so.

The way it was being done, Jones and Shortt just used a
bright lamp to produce the absorption spectra and that produced
a lot of heating, for example in helium which is then boiling
vigorously. That's why you couldn't be really sure of the
exact temperature of the sample. We couldn't really do what I
would 've liked to do, which was to go carefully through the
transition temperatures --which you could have done if we'd
gotten the lasers tuned to that, once we knew where the lines
where. We couldn't use the laser to search for the lines
because it would take forever to search for lines, like looking
for a needle in a haystack. So we had to use a conventional
spectrometer.

Tower of Babel

Riess: In the introduction to this book it says that tunable lasers

were taken up by scientists who were both laser physicists and
spectroscopists. Spectroscopy was a separate branch of
physics? I don't understand at what point one elects to be A
or B.

Schawlow: They probably drift into it. Laser physicists would be working
on lasers primarily, and a spectroscopist might use
spectrographs as they all had done before. And there always
have been some. Spectroscopy was the hot field in the 1920s,
and then it was considered a backwater in the thirties, the
forties. However when they had lasers, that gave them a
powerful new tool and they could do a lot more in Spectroscopy.

Riess: When we talk about astrophysics or physical chemistry or laser
physics or theoretical physics, these are discrete specialties
but they all have to be taught in a university?

259

Schawlow: Some places have specialized courses in them. We didn't

really. We just sort of thought if you signed up to work with
a professor doing things in that field, then you have to read
up on it, teach yourself, learn some of the techniques from his
laboratory, and go on from there. But you do have a Tower of
Babel effect that it is getting harder and harder to understand
people in different branches of physics.

Riess: All with their own journals.

Schawlow: Yes, Physical Review used to be one journal, but now it has
five sections I think. One of these is nuclear physics,
another one is particle physics. I think there's even one on
theoretical physics. Section A is atomic and general physics--
I don't know, I used to get the whole thing, but they'd stretch
from a volume of about this big for a year to this big. And
very expensive, too, and you just couldn't store it.

Riess: Doesn't it mean that people get more out of touch with each
other?

Schawlow: Yes. The only thing that brings them together is the things
like Science and Physical Review Letters which has short
articles from the various branches of physics. But even there,
I find I can't really understand much of the things that are
out of my field.

Riess: Do you use your computer as a way of keeping up with physics?
In other words, do you get on to the web?

Schawlow: No, not really. The library has Physics Abstracts for the last
few years and it's sometimes useful to search there, especially
if you know the name of a person. The particle physicists,
which is a very narrow field because they only have a few big
accelerators, and are all working on similar problems, they're
really desperately anxious to get the last word on something,
both the theorists and experimentalists, and they post
preprints on the web and people eagerly examine them, but I
have never wanted preprints. When I see the article I want to
do it once and not have to see an abstract and then later wait
to get the full article.

Riess: Why are they so desperate?

Schawlow: It's a matter of getting something, an idea, that they can

elaborate and publish something before somebody else gets the
idea.

Riess:

More so than in other fields of physics.

260

Schawlow: Yes. Very competitive. I think it's because the accelerator

is so expensive, they can only have a few of them, so there are
only a few problems being addressed at any one time, and a lot
of theorists are chasing the same problems.

Riess: The science writers who are following physicists around, is it
particle physics that they tend to follow?

Schawlow: Astrophysics seems to turn them on most, then particle physics.
Not very often the optical physics.

More on Laser Cooling

Schawlow: One thing that has caught their attention in the last couple of
years is that Carl Wieman, who is one of Ted Hansch's students
--now at the University of Coloradohas carried this laser
cooling to the point that he, with Eric Cornell, were able to
cool atoms down to the low temperature and of sufficient
density that they got what they call Bose-Einstein
condensation. That started with laser cooling and I'm really
not going through all the advances that other people made in
extending laser cooling.

I guess I didn't explain how laser cooling works. It's
very simple. The way we visualized it was that if an atom is
moving and you have laser beams coming from all directions,
from the six principal directions, that if the atom is moving
toward the laser beamthe laser beams are tuned slightly below
the resonanceif it's moving toward the laser beam, the atom
sees the beam has shifted up into resonance, Doppler- shifted.
So it'll scatter light, and every time it scatters a photon, it
loses about a centimeter per second. On the other hand, when
it's running away from the beam that's coming behind it, it
doesn't see it because that's shifted farther down out of
resonance. So this is a way of cooling free atoms without ever
touching or making them condense.

But other people found that by using the internal modes of
the atom, they can get cooling that goes much beyond what we
had predicted. Then they can trap them as pioneered by Steve
Chu. He used a magneto-optical trap. Then they use
evaporative cooling, where they just lower the trap slightly
and the faster atoms escape, leaving it cooled. That way, they
get down to extremely low temperatures, micro-Kelvins, where
Kelvins is one degree absolute. And that's where they were
able to get this Bose-Einstein condensation. Very much more
has been added to it than what we did, but we did start it. I

261

think that's my second most important paper, although I didn't
think of it.

Riess: When was that?

Schawlow: It would be 1975. I worked on writing the paper when I was on
sabbatical in London, in '74.

Riess: "Cooling of Gases by Laser Radiation"?

Schawlow: Yes. Optics Communication.

Riess: You have Ted Hansch as the first author.

Schawlow: Yes. Courtesy. Well, actually, we could have done it either
way.

There was one case where we were discussing it a little
bit you often go through a state of confusion before clarity
emerges when you take on a new problem. It seems almost
necessary. So we were sort of thinking, "Well, we could
scatter light. Let's see, would you want the laser to be tuned
above that? Or below?" We were a little confused. Overnight
we both came to the same conclusion, to tune it below the line.

When we told people about it, we got two different
reactions. One was, "Can't possibly work" because you're
putting in energy and you're heating the thing. That wasn't a
good reason because the laser has very little entropy, it's a
very pure kind of light, it doesn't have a lot of randomness to
it.

Other people said, "Oh yes, it's obvious." [laughs] When
some people said it's wrong and others said it's obvious we
knew we had something pretty good.

Riess: I should think people would be very reluctant to say something
can't work.

Schawlow: Oh, you'd be surprised. I remember people saying lasers

weren't going to work, and they gave good reasons which are
best forgotten.

Charlie Townes, of course, tells about how Rabi and Kusch
tried to argue him out of the maser.

Riess: Did you and Ted Hansch do any work on that in the lab?

Schawlow: No, no. We didn't even try to build or do laser cooling just
wrote this theoretical paper and left it at that, because we

262

really wanted to cool hydrogen and we couldn't do that because
we didn't have a suitable laser for cooling it. So we just
threw it out and let people see it. Run it up the flagpole and
see who salutes, as they used to say on Madison Avenue.

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VI ACCOMPLISHMENTS AND QUESTIONS
[Interview 8: November 26, 1996] i

General Look at How Schawlow Works

Riess: When you were working on a problem, let's say when you were at
Stanford, who did you bounce your ideas off? I mean, is that a
process for you?

Schawlow: I had various students and postdocs and I guess I talked with
all of them. We discussed things informally.

Riess: Would you use Charlie [Charles Townes], wherever he was?

Schawlow: No, I wouldn't use Charlie at all. No, he was doing different
things, he was into astronomy then. And I really wanted to do
my own thing, however insignificant that might be.

Riess: And maybe the case is that one doesn't need to.

Schawlow: Well, I was forty by the time I came here, I wasn't a kid

anymore, I really was old enough that I should be standing up
on my own feet.

Riess: I'm not implying that. I'm wondering about the intellectual
process, whether it's an internal thing--"This could work,"
"But no, that won't work." Does it all go on in the head?

Schawlow: Yes, pretty much. But I did talk with students and I gave them
a lot of freedom. I would sort of say, "This kind of looks
interesting. Why don't you look into it?" And if they were
good, they would find something that everybody hadn't thought
about. But I would have pretty good instincts of things they
could try.

Riess:

264

Some of them were also fiercely independent, like John
Emmett particularly. But mostly they would go in the direction
I had pointed them. I was just interested in exploring a lot
of different things, so different students I would discuss
different things with. We would have our group meetings every
week. They would be pretty informal and I'd try and get people
talking.

When you went to international meetings, was that a very
fertile time?

Schawlow: No, not really. It was sort of a waste of time. I guess I

don't absorb things very well. I enjoyed going to them, but I
don't really remember ever learning anything very clever.

[laughs] I remember the first international meeting I went
to back in 1955 when I was working on superconductivity. The
thing that intrigued me most was to find out about something
called Dexion, which is a kind of oversized Meccano erector
set. Well, people at Bell Labs were already using that, but I
hadn't known it. Everybody at these meetings wants to tell you
what he's doing.

We did have visitors who came by [Stanford], quite a few of
them. It was a place that was sort of on the path when anybody
came to the United States. It didn't seem to matter what part
of the United States they were supposed to be visiting, they
would somehow stop by Stanford. So we saw a lot of people, but
I really don't think that they influenced me very much. I may
have picked up little bits and pieces.

I don't think these ideas we had were very wonderful
anyway, but they were all something new and that was my main
purpose, to do things that were new and not worry too much
about how important they were.

Riess: I need to be reminded that because you're a physicist does not
mean you have a passion for every single aspect of physics.

Schawlow: Oh, physics is much too big. I mean, really the old Tower of
Babel effect is certainly working there.

When I started out when I was a graduate student, I was
interested in nuclear physics. I read pretty much what was
available, and understood it pretty much, but, boy, that's
gotten far beyond me. And particle physics I'd never gotten
into. Even now in laser physics there are so many branches and
so much elaborate theory that I've never been able to get into.
It's discouraging.

265

Riess: Do you think that people have unrealistic expectations of
physicists as problem solvers?

Schawlow: Well, we certainly have lots of problems to solve.

I guess when I look back I sort of regret that I didn't
find the big problems in science, and do something about them.
I just did what I could, whatever lay at hand. As long as it
was something that hadn't been done before I was willing to
explore it- -even though I don't think anything I did really was
of basic, fundamental importance like discovering quantum
mechanics, relativity, or something like that, it wasn't in
that league.

Still, there were a lot of interesting things we turned up,
and some of them provided a lot of work for other people to do
afterwards, to clean up.

Riess: If you say you regret that you didn't work on the big problems,
do you have a hindsight about what those big problems were?

Schawlow: No. Really, I don't think I could have done anything but what
I did, really. I didn't have the instinct, or the theoretical
knowledge. Indeed, of course, by that time the big excitement
in physics was going into particle physics. That was something
that you had to devote your entire self to, become part of a
big team working on a huge project.

When I came here I knew that SLAG was going to be built,
and I hoped that somehow there 'd be some way of getting
involved with it. But it clearly wasn't possible, so I didn't
really try. Anything they did was done to a deadline. You
would get time for a run on one of the big machines, and you
had to get everything ready for that. And of course there was
the earlier stage where you had to go and persuade them that
your project was worthy of time on the big machines.

It was a very competitive business and I really wasn't
prepared for that. I didn't know the background or anything
like that. It was really too formal for me.

Riess: Earlier you mentioned that you organized public seminars at
Stanford which allowed people to come in from industry and
other campus departments . I ' d be interested in hearing all
about that idea.

Schawlow: Well, it was when I first came in 1961. For a year or two I

ran these seminars and then I guess other people took over the
idea. It was a time, you know, when nobody knew anything much
about lasers and there was a lot of excitement. So we had

266

people--! remember once we got Ted Maiman to come. Of course
he had built the first ruby laser. He gave a good talk.

And there were people in the engineering department who
were interested. There was Tony Siegman and his student Steve
Harris. Tony was a professor already and he had been working
on microwave masers, and then started working on lasers, and he
had some students. I guess Harris came along later, and Bob
Byer, who was Harris' student, was later still. They are both
on the faculty, have been for years and years now. We're
talking a long time ago. When was this? Thirty- five years
ago.

I don't remember exactly how long I kept it up, but I think
it gradually became a more departmental sort of thing, and some
of the individual groups were strong enough to have their own
seminars. There is still such a thing going on under the
applied physics department. Once a week they have a seminar
which is advertised both inside and outside the university, and
I guess some people come to it from other places. That's aimed
a little more toward laser engineering than I'm able to
contribute to.

Riess: When you say outside the university, it's not that it's geared
down to the public, but it's geared to industry.

Schawlow: People in industry. There were companies starting up. Like
Spectra-Physics started up to make lasers and was quite
successful at it. Varian had some interest, and Lockheed too.
I don't remember just what companies were involved. A lot of
small companiesWatkins-Johnson did a little work on lasers
and optics technologya number of other companies, some of
which have disappeared. Anybody who was interested could come.

Riess: It sounds like an important thing to get going.

Schawlow: Burt McMurtry, I remember, was one of Siegman' s students. He
did a clever experiment. He wanted to detect microwave
modulation on lasers, and he wanted a fast-responding photo
tube. He realized that he could take a travelling wave tube,
which was intended to amplify microwaves, and if he just shined
the laser on the cathode of that tube it would amplify whatever
pulses were on the laser. So he didn't have to build a tube.
He took a travelling wave tube and shone a laser on the
cathode.

He's done very well. He went and worked for a while at
Sylvania, but then he got into venture capital and has done
very well at that.

267

Riess: I think of putting together that seminar as a way of thinking
larger, and that's my question here. How do you broaden your
view?

Schawlow: I always read a lot of journals. I would subscribe to a number
of journals--! didn't really have time to go to the library so
I would get a lot of journals. For a while I'd keep them, but
after a while I couldn't keep them. But I would skim through
them every day as more would come in, and catalogs too, looking
for ideas of equipment.

I went to the meetings. The Optical Society would have
one. And then eventually the Quantum Electronics Conferences
would have exhibits. You'd see some new apparatus and get some
ideas of things that you might use. And I'm sure I did pick up
some ideas there.

Prize-winning Work--Rydberg Constant

Riess: Three of your accomplishments are listed in the book on the

Nobel Prize winners in physics: the observation of the complete
hyperfine structure of a molecular iodine line; the first
optical measurement of the Lamb shift in atomic hydrogen; and
the most precise measurement of the Rydberg constant in
hydrogen. '

Schawlow: I have to admit that Hansch really did most of those things. I
encouraged him and provided equipment for him, but the iodine
thing was really done while I was away. I had, however, bought
a krypton laser thinking that it would be useful for something
or other. So it was there. I had Marc Levenson working with
it to make it very monochromatic for some Brillouin scattering
studies.

Hansch did have the idea of getting rid of the Doppler
broadening from the thermal motion by sending two beams in
opposite directions through the cell containing the gas. Then
he would chop one beam and then look at the other beam to see
if it was modulated. If the beams were tuned either below or
above the center of the absorption line, they wouldn't interact
because they'd be seeing atoms going in different directions
because of the Doppler shift.

l Nobel Prize Winners, Physics, edited by Frank N. Magill, Salem Prize,
Pasadena, 1989.

268

However, when they're tuned just to those atoms that were
not moving at all, or perhaps moving a little sideways, they
could interact with the same atoms , and the one beam that was
chopped would saturate those atoms and decrease their
absorption and so let more of the probe beam through, so it
would modulate the probe beam. This was a very clever idea
that Ha'nsch had.

Also a similar idea, about the same time, from Christian
Borde--it actually has roots in the things that had already
been done in spectroscopy of laser gases, where they'd noticed
the dip when they were tuned to the center of a line. Because
there they have two beams going- -this is for the gas inside the
laserthey do have the two beams going in opposite directions.
But what Ha'nsch introduced was using two beams externally and
chopping one of them so that you could sense or detect the
other.

Well, he had this thing, and he also had found a way to
tune the pulsed lasers so that they were fairly monochromatic,
a fairly narrow band. You could tune those anywhere in the
visible. So I said, "Look, if you want people in physics to
pay any attention to you, you should look at hydrogen." That's
the one that people really think they understand, it's the
simplest atom.

So he went to work and he did it, built a gas discharge
chamber for producing atomic hydrogen and passed the two beams
through that, and was able to resolve the fine structure in the
hydrogen spectrum.

Well, at first he did that, we thought, "Maybe that'll
permit us to measure the splitting." But it turned out that
they were already well-measured from microwave studies, so what
was left was to measure the absolute frequency of the line.
Certainly after your question before of "Who did I talk
with?" well, certainly I talked a lot with Ha'nsch after he
came and discussed ideas with him.

So the thing you could do was measure the absolute
wavelength. Now, even if you'd known where all these lines
were under this Doppler-broadened spectrum, you couldn't really
tell exactly where the center of the lines were because you
didn't know the relative intensities of the components. So
once they were resolved he could start measuring the absolute
wavelength and therefore get a value for the Rydberg constant,
which is one of the fundamental constants of physics. It
measures the binding between electrons and nuclei in atoms. He
did improve the accuracy of that by about a factor of ten or
so.

269

Since then, he's gone on, and others have too, and they
have improved the accuracy by maybe a factor of a million or
so. That's a complicated business.

Quantum Electrodynamics

Riess: What is that kind of accuracy good for?

Schawlow: Only for basic physics, I think. Well, a hydrogen atom is
something they think they can understand quite completely
through quantum electric thermodynamics . Indeed they can
calculate the energy levels with great precision in the
splitting, in the Lamb shift and so. So one needs to verify
that to see whether that really is exact. It's a test of
quantum mechanics. So far it's passed every test.

The calculations have become extremely complex. They have
to use more [Richard] Feynman diagrams than the ancient
astronomers used epicycles. But there's a systematic procedure
for doing these Feynman diagrams. Although it requires big
computers and a lot of patience, still some theorists do go on
calculating them, and so far they agree very well. In the
latest measurements they can see an effect due to the size of
the nucleus, which could be ignored in the earlier work because
the nucleus is much smaller than the electron's orbit.

So far they haven't found anything wrong with quantum
electrodynamics, which in a way is a little disappointing
because you'd hope to discover something new and exciting. But
it's essential to test these theories as well as you can, and
they can test them much, much better than was ever believed
possible in earlier years.

Riess: The search for something wrong opens another avenue.

Schawlow: That's the way physics goes, really. A lot of the time you

hope something will not work. You have Michelson's experiment
on the ether drift and it turns out there wasn't any. Then
Lamb and [J.R.] Retherford in 1947 or so detected a Lamb shift
between two levels in the hydrogen atom that were thought to
have exactly the same energy, the 2S and 2P levels.

There 'd been some hints of that before, even some
measurements that had indicated it, but others had disagreed,
so it was not clear until Lamb and Retherford used a radio
frequency method that didn't have to worry about the Doppler
broadening of the spectral lines. And of course that's what

Riess:

Schawlow:

270

Lamb got his Nobel Prize for. It was one of the things that
inspired [Shinichiro] Tomonaga and Feynman and [Julian]
Schwinger to develop quantum electrodynamics , for which they
got their Nobel Prize.

Those quantum electrodynamic calculations have been refined
very much. Interestingly enough, Paul Dirac, who developed the
relativistic theory of quantum mechanics in 1928 or something
like that, never liked quantum electrodynamics. I heard him
talk about it at one of the Lindau meetings of the Nobel Prize
winners, in 1982.

I happened to have a tape recorder with me at that meeting
and I taped Dirac 's talk and gave a copy to my friend George
[W. ] Series--! transcribed it and he got permission to publish
it in the European Journal of Physics. Essentially Dirac said
that quantum electrodynamics is not a real theory, it's just a
prescription for calculating, but it's an awfully good
prescription for calculating. [laughing]

One keeps hoping there will be some much simpler way of
looking at what should be a simple thing with just one electron
and one nucleus. But they have to take into account the
interaction with the radiation field, polarization of the
vacuumit becomes extremely complicated to try to do exactly,
but apparently they can, and so far neither that nor other
precision experiments, like the ones that Dehmelt got his Nobel
Prize for, have shown anything wrong with quantum
electrodynamics .

They keep on pushing, and I'm sure that Hansch and others
will get another factor of ten or so and send the theorists
back to their pencils and their computers.

Would you characterize this as the search for the secrets of
the universe?

Yes, it is part of that, yes. It's part of the search for the
laws that govern the universe. You test the ones you know and
see if anything 's wrong. If so, then you may have to get a
totally different approach that looks quite different but
somehow includes all the old results. An example of that, of
course, is relativity reduces to Newtonian mechanics if the
speed is not close to the speed of light. If it's much less
than the speed of light, then Newtonian mechanics is very good,
yet it looks quite different when you do relativity.

One hopes that maybe there ' 11 be some new way of looking at
things that'll make things simpler. But making them look
simpler is not enough, they have to predict all the old

271

results, and now there are very many good results of quantum
mechanics, and also some predict some new ones that differ from
quantum mechanics. That's still an important search, but it
takes a certain amount of courage to say that that's what
you're going to do.

On the other hand, you can go ahead and measure some things
which might possibly throw some light on it. But one has a
feeling sometimes that it's sort of like the drunk who is
looking for his lost quarter under the lamppost, "because
that's where there's light" [laughter] you didn't necessarily
expect it there.

These things where we've made discoveries beforepeople,
for instance, have tried the Michelson Morley experiment using
lasers and increased the accuracy by many orders of magnitude,
but the results are still the same. And so it is with quantum
mechanics. Perhaps if a surprise is found it won't be found
there, I mean, in doing the old experiments with better
accuracy. But you don't know. So you do what you can.

Riess: Do you have some thoughts on the work of Stephen Hawking?
he fit in anywhere here?

Does

Schawlow: I've never had any interaction with him, I've never met him.
He's a theorist, and he does interact with a number of other
theorists. They have discussions and arguments, probably. But
basically in the end I guess it's his own ideas that he writes
up.

Riess: He has quite a public following, like Feynman had.

Schawlow: Yes, he's well known because he writes so well and because he's
so handicapped. But there are others in cosmology, quite a few
of them whowell, they publish obscure papers that are hard to
read. They don't always agree with Hawking, and sometimes
they're right, sometimes he is, or sometimes one doesn't know.

Scientific American published a debate between Hawking and
Penrose a year or so ago about some aspects of cosmology. I
wasn't really interested enough to try and decipher it very
thoroughly. I think a lot of it is speculative.

Schawlow: I know Hawking "s work only secondhand through popular accounts,
but I believe he did show that black holes could radiate away
some energy because of quantum effects, quantum mechanical
effects, which hadn't been thought about before. Otherwise,

272

black holes --any thing that fell into them was going to stay
there forever and had no way of getting out.

I think he has convinced people that there are quantum
effects, that they do radiate something or other. Of course,
there's a lot of radiation from the region around the black
hole, a lot of material that's drawn into it and accelerates as
it's going in. But it's a different frontier of physics.

And then of there are the particle physicists who feel that
they have the frontier. That if only they can get some bigger
machines they may find the Higgs boson which can explain why
all the other particles have mass. Of course I don't know who
explains why the Higgs boson has mass, but I don't understand
that that well.

Riess: What you're doing is lining up a list of what we would call the
sexy questions in physics.

Schawlow: Yes, yes. And I've never really worked on them, I sort of poke
around the corners and see what I can find.

Riess: And yet the laser, at a certain point, was the sexy discovery.

Schawlow: Yes it was pretty sexy for a while, at least among the

engineers. It also attracted a lot of theorists who wrote
elaborate papers which I couldn't understand.

First of all, we thought of it in the semi-classical way,
thinking of the light wave as being a classical wave to
interact with quantum mechanical atoms and use the quantum
mechanical process of stimulated emission. But this didn't
satisfy people like Willis Lamb who wanted to quantize the
field too. And you can do it, but it gets a lot more
complicated.

I think it was in connection with that work that he
proposed what's now known as the Lamb dip- -not the sheep dip,
the Lamb dip [laughter] --where if you tune gas lasers like
helium-neon exactly onto the center of a line, then the output
drops. That's because the two waves from the opposite
directions are drawing on the same supply of atoms. This was
certainly a predecessor of Hansch's Doppler-free saturated
absorption experiment.

Now, let's see, there was a third one that you mentioned.

273
Hyperfine Structure of Iodine

Riess: We talked about the Rydberg constant, the Lamb shift, and the
first was the hyperfine structure of iodine.

Schawlow: Iodine, right, yes. Well, I went with some of these things. I
had Marc Levenson measure the hyperfine structure of all the
lines that he could reach. This was a case where he was using
a gas laser that did produce a number of different wavelengths,
maybe a half a dozen or so in the visible, but it wasn't
continuously tunable. However, the lines were quite narrow
when you could tune them.

So Levenson looked at those lines of iodine that he could
reach and he studied the systematics of how did the hyperfine
splittings change. There 'd been some theorists who had
suggested that the quadropole splitting, which is caused by the
shape of the nucleusnot being spherical, they're sort of
football- shaped- -would change markedly as you got up toward the
dissociation energy of the molecule, which he could approach.
That didn't happen, so that was something he found.

Then there was a magnetic splitting also. That did get
large as he got close to the dissociation, which he interpreted
as a mixing in of another state that was near the dissociation
level that had a different magnetic property. When they get
close together they mix in a little bit of the properties of
that other one. So we followed up on that.

His Ph.D. oral came just after Linus Pauling had come to
Stanford. Pauling wanted to see what was going on in physics,
so he volunteered to preside at a Ph.D. oral and Levenson was
the first one, which actually was not so far from things that
Pauling had done in molecular theory. It certainly was an
extension of them. Pauling was quite polite and friendly, but
I'm sure that must have made Levenson a little bit nervous
because he was the great expert on molecular theory at that
time, or had been.

Let's see, then I posed some alternative methods for really
sensitive detection instead of using absorption. The trouble
with iodine was that at the lowest pressure we could get by
cooling it the lines were still pressure-broadened. That was
not because we couldn't cool it more, but if we did there 'd be
not enough vapor to see, there wouldn't be enough absorption to
see the changes in the absorption. So I thought of using the
fluorescence because when it is excited it fluoresces. And we
were able to go down a number of orders of magnitude.

274

About that time, I guess, continuous wave dye lasers were
beginning to come in, and Bill Fairbank, Jr., who was the son
of one of my colleagues, was working for me, and I suggested
that he build a continuous wave dye laser. Well, the gain of
the dye lasers, the continuous wave one, was not very high, and
you couldn't put tuning elements in it the way you could in the
pulsed dye lasers, where you had a lot of gain. So this thing
was rather a Rluge .

Riess: Rather a Kluge?

Schawlow: Kluge--K-l-u-g-e. Haven't you ever heard of Kluge?

It was a complicated thing with external tuning elements
outside of a laser cavity, and it was difficult to tune. But
you could tune it to the sodium resonance, one of the bright
yellow D-lines, and then use this fluorescence to get a
relative measure of how much was there. He was able to cool it
down to below zero Celsius, I think minus twenty or something
like that, and measure the vapor pressure of the sodium at
about a factor of a million lower than it had ever been
measured beforeas it went down in temperature.

So this was a very sensitive methodin fact, we realized
that at the lowest temperatures there probably was only one
atom at a time in the beam, that you'd accumulate light for
some time. In fact, at those temperatures the mean-free path
between collisions was greater than from here to the moon.

Riess: The mean free path?

Schawlow: Between collisions of sodium. There were so few sodium atoms
that they just wouldn't ever collide. They'd collide with the
walls of course, but not with each other.

Riess: Well, that's a very neat experiment.

Schawlow: Yes, I thought that was kind of cute. He built this thing, and
it really wasn't good for much, so I sort of pulled the rabbit
out of the hat by suggesting he measure the vapor density. And
he did it. Of course I didn't do it.

Riess: Your responsibility in giving ideas to people just starting
their careers--it can be a make or break thing, can't it?

Schawlow: Yes, I think so. And sometimes I would find students just
couldn't do things the way I suggested and I'd have to give
them something simpler, or get a new student to come in and
help them.

275

Students work in different ways. Most of them are much
stronger in formal theory than I was. I think I annoyed some
of them because I'd do more hand waving because I was trying to
understand the basic processes rather than the details of the
theory.

The Apostolic Succession Phenomenon

Riess: In the process of putting a student together with an idea, do
you have to have a grip on the student ' s psychology or his
whole modus?

Schawlow: Well, you try. Sometimes you'd guess, and you wouldn't always
succeed, as I say. Sometimes they couldn't work that way.

I had one student who just could not work by himself. He
started out--as I often did, I'd have a beginning student work
with an older one. I used to call it Apostolic succession,
[chuckles] So John Holzrichter worked with John Emmett, and
Holzrichter was a brilliant experimenter and has gone on to do
nice things at Livermore. He was in charge of building their
first big laser before fusion, and now he's in charge of their
independent research- -they have a certain amount of freedom to
do things on their own.

When he was finishing up, I had Jeff Paisner start out to
work with him. Holzrichter and Paisner did very nice things
together, and I thought Paisner could just go on and do a bit
more of the same. But nothing happened at all.

And then Serge Haroche came from Paris, a very brilliant
guy, a wonderful person, and still a very good friend. Serge
Haroche is now the head of the physics department at the Ecole
Normal in Paris, which is one of the Grandes Ecoles, a very
distinguished position. He had a bright idea of looking for
what's now known as quantum beats, where you put a pulse of
laser light on sodium vapor, tuned to the absorption line. But
it would be a short pulse and the spectrum was broad enough so
that it would excite several hyperfine components, sort of in
phase. Then the thing afterwards would radiatewell, it was
sort of like he lined up the atoms and then they precessed,
like a searchlight that goes by you and you get alternations of
lighter and darker.

Well, I got Paisner working with him, and things were going
great, and I'm sure that Paisner made a real contribution.

276

Then Haroche left, and I said, "Well, you could do a little bit
more here" and nothing happened.

National Ignition Facility Work, and Military Sponsorship

Schawlow: Finally Richard Wallenstein came from Germany and they did some
nice work on quantum beats in molecules. He's a very good man,
Jeff Paisner is, and he's done well at Livermore and published
some nice work. He is now in charge of the design of the
National Ignition Facility, which is going to be a super giant
laser for fusion.

Riess: I remember you mentioning that, and I was thrown by the name.

Schawlow: It's a giant laser, or set of laser beams, that will be focused
on a little pellet of heavy hydrogen. They will get enough
energy so they hope that they get more out in the resultant
explosion than they put in. The laser will heat it hot enough
and compress it so that the heavy hydrogen combines to produce
helium and release energy that way.

Riess: For a practical energy source?

Schawlow: They say that if you could tame it you could provide the

world's needs for practically foreverthere' s enough heavy
hydrogen in sea water.

But in fact now the sponsorship is military because they
want to simulate hydrogen bomb explosions, and they can do that
and really make measurements on them that they couldn't make on
bombs, particularly because they're afraid that there might be
a treaty banning all nuclear tests, which is I think quite
possible. Then they only way they could do research on trying
to understand and improve the hydrogen bomb would be with this
simulation.

Riess: Tell me why understanding and improving the hydrogen bomb is an
important way to go.

Schawlow: Look, I don't understand the military mind, at all.

However, it's certainly possible that if they could tame
the thing- -the trouble is that as the work has gone on the
threshold has gotten higher and higher, so that they will have
to put in something more than a million joules in one pulse.
And the output will be something more than that, so it's a very

Riess:
Schawlow:

277

big explosion that they'll have to contain to convert it into
usable energy.

They have some schemes, including having the thing in a
cell whose walls are coated with liquid lithium that would
absorb the neutrons from the blast and convert that into heat
and then electrical power. But these things are still untried,
and it isn't easy.

As I've said, it reminds me of the story of the king in the
olden days who wanted to have some oak trees in front of the
palace and told his prime minister, "Get a hundred men tomorrow
and have them start planting a thousand oak trees in front of
the palace." The prime minister says, "But Sire, why the
hurry? Those oak trees won't be fully grown for a hundred
years." The king said, "A hundred years? Have them start
today." [laughter)

The possible payoff is enormous if you could tame nuclear
fusion. Of course, this competes with the gaseous discharge
work on nuclear fusion, the sort of thing that's been going on
at Princeton. They both have difficulties.

If the military will pay, that's the way to get it paid for.

Well, it is, but I think the military really want that
information. They want to know everything about hydrogen
explosions, thermonuclear explosions.

Work and Publications with Students

Riess: I'd like to talk more about your students. You've already
talked about many of them in the process. The first two
graduate students to join the Schawlow group in 1961 were
George Francis Imbusch and Linn Mollenauer, and you've talked
about them.

Schawlow: We had a lot of fun together with Imbusch and Mollenauer. I
think I've said before, Imbusch was very quick at getting
things done.

Mollenauer was not quite so quick but he was a deep
thinker and usually came up with something I hadn't thought
about. He's done very well. He's been at Bell Labs for many
years and he really was one of the first to show that optical
solitons, solitary waves, could exist in glass fibers and that
they would be a very good way to transmit information at high

278

speed because these things retain their shape, even if there's
attenuation. And they can be replenished; if a signal gets
weak, they can be reconstituted exactly the same as they were.

Riess: Perfect for Bell Labs.

Schawlow: Yes. Well, they haven't decided to put that system into work
because this is a huge investment in these fibers, but still
there and at other laboratories around the world it's being
extensively investigated and looks like a real possibility for
the very high speed communications.

Imbusch, despite his German- sounding name- -I think his
family came from Austria originally- -his father was Irish and
was a cabinet maker in Limerick. Imbusch went to University of
Galway, where he could get a free education if he'd do it in
Gaelic, in the Irish language. After finishing his Ph.D. he
spent a couple years at Bell Labs, and they would have very
much liked to keep him, but he went back to Ireland and has
been a professor at Galway, and has continued to work on the
spectra of ions and solids, and energy transfer among different
ions. I think he's been a dean; he's certainly been an
important official in the University, and in Irish physics in
general.

Riess: Did Bell Labs ever underwrite work out here?

Schawlow: Well, they certainly never underwrote anything for me. I know
when I was there, there was a feeling that, "Well, we're
supporting science by providing new results from our own
laboratories." They had given grants and fellowships, but I
never had any direct contact with that. They never seemed very
interested in what I was doing. As I say, I was going my own
way, trying to stay out of the way of the thundering herd. I
didn't want to get trampled on.

Riess: A student named Warren Moos "joined the fledgling laser
spectroscopy group in 1961."

Schawlow: He was a postdoc who came from Michigan and he was interested
in photochemistry and several other things . He actually had a
student in engineering, Richard Soref, work for him on
nonlinear optics.

Moos went to Johns Hopkins and became an assistant
professor and has been a professor for many years. He switched
to rocket astrophysics, where they send up rockets above the
atmosphere and can photograph things in the ultraviolet and
infrared, although only for a relatively brief period. I think
he's done well at that, but I haven't followed him in detail.

279

Riess: Now, when we're talking about students, these are really
graduate students. These are not postdocs.

Schawlow: No, I didn't have very many postdocs. Bill Yen was one, Moos
was another.

Riess: Bill Yen came in 1962.

Schawlow: Yes. There were two students from Washington University that
were somehow being pushed for postdoctoral jobs. One of them
was Yen, the other one was Schwettman, Allan Schwettman, and
he's still here. He worked for Fairbank on the superconducting
accelerator, and he still continues to work on that even though
Fairbank is long gone.

Riess: Did Bill Yen originally get his education in China?

Schawlow: I think not. His father was in the diplomatic service, and he
didn't live in China very long. He said when he was about
fourteen or so, he had to go back to China, to Shanghai. He
grew up in Mexico City, mostly. His father was in the
Nationalist diplomatic corps, and later was ambassador to
Venezuela. I used to kid Yen about being the only person who
spoke Chinese with a Mexican accent. He took some high school
work in Shanghai. He said that was rough because he really had
a lot of Chinese to learn and it's a difficult language.

But he came back to the United States and went to the
University of Redlands I think, in California, and then to
Washington University at St. Louis, where he worked on nuclear
resonance.

Riess: And he was in the initial group with Imbusch and Mollenauer?
Schawlow: And Moos, yes.

Imbusch, I think, worked mostly on magnesium oxide, with
chromium in it, which is another crystal that's a little
different from the sapphire because the chromium ion is really
in a site of cubic symmetry. Although chromium has a charge
three, and the magnesium that replaces it has charge two, so
there has to be some charge compensation somewhere else in the
crystal.

Do you have the bibliography that I give you, the
publication list? It might help me remember who did what.

[Riess passes bibliography to Schawlow]

280

Schawlow: Yes, here. We collaborated a little bit on energy levels in
concentrated ruby with Paul Kisliuk and Mike Sturge at Bell
Labs--Mike had come from England and had taken over my big
spectrograph at Bell Labs. We studied temperature dependence
of the width and position on the strong red lines in chromium
and vanadium in magnesium oxide, again with some collaboration
from Sturge at Bell Labs, and [D.E.] McCumber, who's a
theorist. [Number 62 in publication list.]

Riess: This was in the early years?

Schawlow: Yes, 1964. Then Yen and [W.C.] Scott, who was a student,

worked on praseodymium in lanthanum fluoride. [Number 66 in
publication list.] We got into that partly because I was
consulting with Varian. They were somewhat interested in
getting into more fundamental research and they hired a crystal
grower who liked to grow lanthanum fluoride crystals and could
put various ions in it.

Riess: Let's continue to review work you did with this group.

Schawlow: I probably shouldn't spend too much time on it, but you asked
who some of these people were. Jake [J.Y.] Wong. "Far
infrared spectra of V4+ and Co2+ single ions in corundum."
[Number 78 in publication list.]

There were so many different things we did. We were trying
to understand the splittings of these satellite lines in ruby
and we had at one time tried to identify two of these lines
coming from the same kind of chromium ion pairs, in which case
there should be a far-infrared line connecting these two levels
that show the splitting. Well, we thought we would check that
out, but we were beginning to doubt it after we studied the
thing a little more carefully. Jake Wong was the chief man on
that. Mike Berggren helped with that too.

Then it was Ed Nelson who built a far infrared spectrograph
for us. [Number 80 on publication list with E.D. Nelson and
J.Y. Wong.) I got a huge rod of ruby, about six inches long,
dark ruby, and about three-quarters of an inch in diameter.
And there was no absorption at those wavelengths, but on the
other hand we got a more moderate sized crystal of aluminum
oxide containing some titanium and we saw the line . I told you
that story earlier. [See p. 239] That was work with Nelson and
Wong. Nelson built the spectrometer.

Steve Johnson came in the late sixties, and he did some
work on excited states in ruby and emerald. He's now at the

Riess:
Schawlow:

281

University of Utah working on biomedical imaging. I had gotten
him to try and build a novel kind of spectrograph.
Photographic plates have low quantum efficiency, but they do
take all the light all the time. I thought a television type
pickup tube would do that even better because it's more
sensitive and gets all the light all the time.

Johnson worked for several years building such a
spectrograph using an image orthocon, which was state of the
art in those days but unfortunately not a great choice for this
because it's kind of a finicky thing, not as stable as one
would like for a spectrometer. Now, it's very common that
people use what they call optical multichannel analyzers, which
usually use an array of diodes to take all the light all the
time and read it out in scans.

Johnson was very stubborn. At one time we had some money
left over and I wanted to buy a commercial tv camera setup and
he wanted to build his own. He spent several years doing that,
but he learned a lot about imaging, and so he's gone into
biomedical imaging ever since.

Another student I had was Stan [E.] Stokowski, who had done
an undergraduate thesis with Charlie Townes at MIT, the only
one who ' s ever worked for both of us . I had him doing some
studies of line shifts of chromium in strontium titanate, which
is a ferroelectric crystal. It's a crystal where the electric
field moves the ions around rather easily so you get a large
susceptibility. We actually were able to finally see a change
in the intensity of the lines as well as the positions when you
applied an electric field. [Number 91 in publication list.)

Much of this sounds like chemistry to me .

It was close. I was a member of the division of chemical
physics of the American Physical Society. This sort of stuff
was done in the Electrochemical Society too, although I never
did get involved with that.

Peter Toschek?

He was just a visitor, a nice guy. Hansch worked with him for
his Ph.D. thesis. He insisted he wasn't Toschek's student,
Toschek was a postdoc there, but they both learned lasers
together. Neither of them had done anything with lasers
before.

Larry [S.] Wall did work on stress-induced phase
transitions in strontium titanate. [Number 101.] I had a lot
of students. I had forty altogether.

282

Chinese Physics Graduates

Riess: You had a number of Chinese students. How was their

orientation different from American students? Can you make any
generalizations?

Schawlow: Wong had his undergraduate education in this country, at
Princeton. He was from Hong Kong and certainly fluent in
English.

Riess: And Zugeng Wong?

Schawlow: He was just a visitor [1982-1983], Wong Zugeng.

I visited Shanghai in 1979. That was the first exchange
where the Chinese Academy and the National Academy of Sciences
agreed to exchange a certain number of lecturers. Each one
would go to a different place and they'd bring students from
all over China to hear the lectures. So I went to Shanghai
Normal Universitylater it became East China Normal

University. That was supposed to be a
had considerable research going on.

teacher's college but it

Riess:

There was a professor there named I-shan Cheng who had
gotten a Ph.D. at Ohio State in molecular spectroscopy in the
1940s. They weren't giving Ph.D.s at Chinese universities at
that time. But they had a number of people doing research,
generally under his direction, and he asked if we could have
some of them come visit and work in our laboratory. They
supplied the money for support for them so 1 didn't have to pay
anything. So I said okay.

And there was also Xia Hui-Rong. Xia is the family name,
but she was the wife of Wong Zugeng. She was a good physicist,
and she died just a few weeks ago in a bicycle accident on the
campus of East China Normal University. She was here for a
year, and then she was at the University of Colorado for
another year, I think. Her husband, Wong Zugeng, was also a
pretty good physicist. I think he became head of the physics
department there.

Anyway, she was in a bicycle accident. They don't wear
helmets in China, and she somehow hit her head, was in a coma
for a week, and died.

Then there's Zhang Pei-Lin?

283

Schawlow: Zhang Pei-Lin. He also was not a student, he was a visitor in
1983. He was from the Institute of Physics in Beijing and he
was quite a good man too.

There was another Wong in there, Wong Zhao- Young, who was
from Fudan University in Shanghai. He was only able to stay
for nine months, so he didn't get as much done as the others
did. He later became head of the physics department there, but
then much to my surprise he moved to Hong Kong and became a
member of the physics department at one of the universities,
Baptist University, I believe.

I hate to go on print saying that I just can't remember
people. And I can't remember a lot of people. It's terrible
at times.

Riess: Can you make a generalization about the approach to physics of
the Chinese, or the training?

Schawlow: I think the general thing I felt when I visited China in '79,
the first time, was that they were very capable and had built
just about every kind of laser that had ever been in print, but
they didn't have any idea what to do with them. They really
didn't have very creative ideas.

The people in Shanghai under Professor Cheng were trying to
measure atmospheric pollution using two carbon dioxide lasers,
one of which was tuned to an absorption line of a pollutant and
the other was tuned off it . And that ' s a very good way to do
it, and they were actually measuring some pollution from smoke
stacks. But most of the other people I saw really didn't seem
to have any very good ideas. I'm sure it's much better now.

The other thing I found is that they were trained very
narrowly. They wouldn't know anything at all about nuclear
physicsif they were going into laser physics and optical
physics that would be all they'd know. And they'd know that
pretty well, what was in the books they would know. But they
wouldn't know anything at all about other branches of physics.

Riess: Did you feel that they looked to you as a leader more than
other students might have, that the reason they didn't have
ideas was because somebody else was always supposed to have
ideas? Or they didn't know what they were looking for because
somebody else usually told them?

Schawlow: Well, this was when I visited China. The ones who came here,
yes, they developed ideas as they went along. Again, I would
kind of aim them in some direction and let them go, and then
they thought of things, they developed ideas.

284

Particularly Yan Guang-Yao. He came in that group in 1979.
Professor Cheng, who had been very badly treated during the
Cultural Revolution, I think sort of looked after Yan, who
wasn't a Communist--! think the rest of them were and because
of that he was sort of low man on the totem pole around the
university. But Cheng particularly suggested that we take him,
and he was really the best of the bunch as far as producing his
own ideas, and carrying out experiments too, although the
others were okay.

In 1984 when I visited again I didn't have any postdocs and
was sort of lookingit would be nice to have somebodyso I
invited Yan to come back, and he came with his wife and son.
Now he has no intention of moving back to China and he has his
green card I don't think he's a citizen yet. He worked on his
Ph.D. for quite a long time.

He was here first just as a visitor. Then when we could we
made him a graduate student, when he could do that without
having to go back, and he worked there for quite a while. As
soon as he could finish his Ph.D. without having to return he
finished it. He'd written twenty papers by that time. Then
well, he was close to fifty and his English accent was pretty
bad so it would have been hard for him to find a teaching job,
but a job opened up running the lecture hall demonstrations at
Stanford and he took that on and is doing a good job there.
It's not really a research job, but it does require some
knowledge of physics and apparatus, which he supplies very
well.

Riess: The dead horse that I'm beatingthe world view of someone

educated in China is not so different that they don't look at
questions of physics in a very different way?

Schawlow: I don't think so, no, not the people I knew. They seemed very
normal .

I think now, of course, laser physics in China, and
spectroscopy, are doing some original things. They have some
crystal growers who have developed some special crystals for
harmonic generation and mixing of different wavelengths that
are some of the best in the world, producing materials that are
sold everywhere.

I didn't have any students who were directly from mainland
China. We did start admitting a few in the eighties. We had
to keep the numbers down because we're not a very big
department and we could easily have filled the place up with
Chinese students. I think, though, that the ones who came did
pretty well. They had strong theoretical grounding. It would

285

have been hard to sort them out, but T.D. Lee had arranged for
examinations to classify these people and that was a big help.

Riess: What do you mean "sort them out"?

Schawlow: Well, to find out which ones were really good.

Riess: You mean at the point where they're applying?

Schawlow: Yes.

Riess: Where was T.D. Lee?

Schawlow: He's a professor at Columbia, from China originally. He got a
Nobel Prize in the 1950s for discovering the nonconservation of
parity. Both he and C.N. Yang, who shared the prize with him,
they've both come from China and they've done a lot to try and
help Chinese physics.

Summing up the Seventies

Riess: When Ted Hansch came in 1970 the original whole balanceit ' s
not like a balance of power, but something shifted.

Schawlow: Yes, sure, the direction of things.

We had some money for the first time. We had that
equipment grant and tunable lasers had just been discovered,
and he improved them considerably. But we could, for the first
time, do some laser spectroscopy. Up until then we'd just been
mostly studying the properties of materials related to lasers,
we hadn't really been doing work on lasers so much except what
Emmett did, or building lasers for special projects. So we
switched over, really cut down working on solids and I think
Gary Klauminzer was probably the last one to work on ions in
crystals.

Then I sort of started following up on some of the things
that Hansch had started. Well, some things were my own. I had
worked on Brillouin scattering, and also the intermodulated
fluorescence, which was the way to get sensitive detection of
weak lines which has been used by some other people too.

Riess: In fact, the set of questions that you had initially asked as a
graduate students were beginning to be answered at the end of
your research.

Schawlow:

Riess:

Schawlow:

Riess:

Schawlow:

286

Yes, certainly getting rid of the Doppler broadening, that was
pretty well under way with the saturation of intennodulated
fluorescence and so on, and other methods of polarization and
intennodulation.

But it's the old story--a lot of things that were terribly
difficult to do at one time, like when I was a student, become
easy, but they're done. [laughs] So you have to keep on
looking for other things.

When Ted Hansch came did your role vis-a-vis students change?

Well, he had his students and I had mine. And I didn't have
much to do with his students. I guess at first even before he
became associate professor there were some of them that were
formally reporting to me but actually being supervised by Ted.

It is true that toward the end I was really letting him
have all the resources I could and really making do with things
that he wasn't interested in, equipment that he was tired of.
So he did cause some constraints on space and money, but still
he was so good that I just really wanted him to have every
opportunity that he could. And of course we were fighting to
keep him because other places were trying to hire him away,
Harvard and Yale among them, and Heidelberg, and then finally
Munich got him.

What was the financial situation in those years?
equipment then.

You had the

I got the equipment grant just about the time he came,
never got another one.

but I

We did have what the National Science Foundation claimed
was the biggest grant in their atomic physics program. They
were used to fifty thousand dollar grants and ours was probably
about three hundred thousand. But it sure wasn't enough for
all the things we wanted to do. We had to pay huge overhead on
any salaries or any supplies. We had to pay employee benefits
of something like twenty-five percent, and overhead on salaries
after benefits, including the benefits, something like sixty
percent.

I think it was true that if I hired a person it would cost
me Just for his salary twice as much as I was paying him. So
that made it very expensive. It was one reason why I stopped
having any postdocs. If somebody came with their own money,
that was all right, but I couldn't afford to hire them.

287

After I retired, a man from the Office of Naval Research
who had been helping us said that he wanted me to have seventy-
five thousand a year so that I could hire a postdoc. Well, I
figured if I hired a postdoc, I couldn't pay less than about
thirty thousand for salary, and with overhead I think it would
be over sixty thousand. That would leave very little money for
equipment or supplies, and I just wasn't able to do it.

Riess: Was that an area where you did battle with Stanford?

Schawlow: No. I'm afraid I just took what I could get. I felt it was
hopeless. Other people were trying to fight it, not I. The
university wanted all the money they could get their hands on.

Then of course they got into trouble with the government
over charging too much. The Office of Naval Research had a
representative at Stanford who could approve our payments, and
usually these were people who'd go along quite nicely with
whatever we wanted to do. But then they got a guy who wanted
to make trouble and he caused a lot of trouble and he found a
few skeletons in the Stanford closet, nothing to do with me,
but they then cut their reimbursement rate for overhead
substantially. I don't think it's ever gotten up to what they
had before though it's still pretty high.

News of the Nobel Prize Putting the Money to Work for Artie

Riess: Let's go now to the happy subject of the Nobel Prize. Tell me
about it, and also tell me what you did with your prize money.

Schawlow: Well, first thing I heard of it was that I had this phone call
at four o'clock in the morning from a radio reporter. He
wanted to know first of all what had I done to get this Nobel
Prize, and I couldn't tell because I had published a hundred
and sixty-seven papers and I didn't know which combination they
were honoring me for. In fact, it was some time quite late in
the day before I got the actual citation, [laughter]

Nowadays and before that, I think usually there's a phone
call from the Swedish Academy. But I didn't get one. I did
get a telegram from the Swedish ambassador I think, but it was
days later that I got anything direct from the Academy.

Riess: There is a picture of you and Aurelia on the telephone in your
kitchen. I take it that was posed.

288

Schawlow: Well, yes and no. I guess so. Anyway, that was early in the
morning, and of course the phone calls started coming. Then
the Palo Alto Times, I guess, wanted to send a photographer.
So Aurelia insisted that I take the phone off the hook and get
dressed.

Schawlow: Yes. This reporter also asked me what I was going to do with
the money. I told him I had an autistic son and that we were
working with some others to try and set up a group home for
autistic people. Well, actually, I did give five thousand
dollars to a Peninsula Children's Center which was trying to
plan something, but what they were planning just wasn't
suitable, so we dropped out of that. They felt that you could
just have a program for a few years, and autistic people are
not going to be cured in a few years.

So then we found a group home for Artie, and we offered to

pay for an extra staff member. We paid them, I think, $2500 a
month or something like that for some months. I think we spent
over twenty thousand dollars on that.

Well, of course we spent a few thousand dollars on the
trip, because I took my wife and daughters and they needed six
evening gowns. [laughter] They borrowed fur coats from
various friends, so they didn't have to buy a fur coat which
you couldn't use in Palo Alto. We didn't go the cheapest way.
We stopped in London both ways, and in New York. We spent
about seven thousand dollars on those expenses. So that
accounts for about thirty-four thousand, and I'm sure the rest
of it all went for things that Artie needed. I've spent
hundreds of thousands on things for him.

Riess: You used that as a public opportunity to talk about autism.

Schawlow: Yes, I did, and it was appreciated by the Autistic Society.
They gave me a plaque.

A wonderful thing came out of it. When we went to
Stockholm, we met Karin Stensland Junker. She was the mother
of an autistic girl and had written a book about her daughter.
Then she got a Ph.D. in clinical psychology working on that.
She told us about a young man who had come to her office and he
couldn't talk--he was twenty-four years oldbut he could type
on the keyboard that looked about the size of a calculator, but
it typed letters instead of numbers and it printed them out on
a paper tape.

289

She asked him, "Could I have some of your tapes?" And he
replied, in Swedish of course, "No." She said, "Why not?" He
said, "You can't read it when the sun shines." Well, it fades
in sunlight, it was a thermal printing.

I thought, "Gosh, if Art could do that!" He might be able
to understand that, but we had no way of telling.

Then when we came home, I was giving talks all over the
country to various Autistic Society people. And in Memphis I
told somebody about this and he said, "That sounds like a Canon
Communicator," and gave me an address in Seattle. It turned
out that they were just modifying it for special handicaps,
like for people who needed to operate it with a stick in the
mouth. But they told me where the American distributor was and
it turned out that was a company that was about a mile away
from my home.

I went over there, and they would 've lent me one, but I
knew it was going to be more difficult so I bought one for six
hundred dollars. And it was a flop. He just hit XXX and ZZZ
and so on.

Well, we've told the full story in that article that we
wrote about him. We tried various things. Finally it was a
couple of years later, almost two years later, that he began to
actually communicate with us.

Riess: So first he resisted it?

Schawlow: Yes. But then we tried other things, like trying to get him to
pick out letters and put them into blocks where they would fit .

Then we got this Texas Instruments Touch and Tell, where
the synthesized voice asks, "Show me the red letter 'R',"
something like that, and then if you get it then they say,
"That's good," or something like that, and move on to the next.

The first week he just didn't seem to know what it was all
about. Next week, he did all right off, he knew the whole
alphabet. Then we tried cards with pictures and with words,
matching words to pictures. He could do that pretty well.
Then we had him picking out words from a magazine page and he
could do that too.

Then we met a speech therapist who showed us how to use a
communication board where you put the words on. You can make
choices, like for snacks or Job tasks. You point to a word.
We thought he might need pictures, but he didn't. With just
the words, he could do it. So he obviously could read some. I

Riess:

Schawlow:

Riess:

290

guess we'd had another teacher for a short while who began to
show us that he could recognize letters. That happened along
there. I forget exactly where that came in.

Then we had this first laptop computer, the Epson HX-20. I
programmed it to show a word with a dash under each letter.
Nothing would happen unless you pressed the right key, then the
letter would appear. And at the end of the word, if he got the
word complete, it would print it out on a strip printer that
was built in like an adding machine printer. He loved that.
He would tear off these things and stuff his pockets with these
tapes until he had used up all the tape.

But this was still not communicating. So then one day I
thought, "Well, I'll let you choose what kind of pizza you
want." We were at the park and we'd usually go for pizza after
that. I put down cheese, sausage, and pepperoni. He chose
sausage by pointing to it. I said, "Let's confirm that by
typing it out." And he typed it out with my hand on his.

Then it was just a week or two later that we were in the
ice cream parlor, and he waved for something over in one
direction. We acted dumb and said, "Let's go to the car and
get the communicator. You can tell us." He typed out "shoes"
and there was a shoe store there, so we bought him shoes, and
that was a big breakthrough.

Your hand on his, of course, is the controversial part of the
whole business.

Yes, I know. But that was the way to get his hand on the
keyboard. And he still seems to want it. He doesn't usually
want to point at anything without a hand on his . Very
occasionally he forgets that he needs that and will do
something. There have been some studies on how to achieve
independence.

It's been hard for us because we'd only see him every few
weeks for an hour or two and we wanted to get the
communication. But I really wish we could work on independence
because we're not always going to be around. Fortunately some
other people have been able to pick it up and can get something
out of it. Some, particularly Martha Leary, and Aurelia when
she was alive, are very good, they can get a lot out of him.
Otherswell, when he really wants something, he can tell them.

He probably really wants you and that's the way of staying
connected.

Schawlow:

Riess:

Schawlow:

291

I guess so, but he doesn't tell me a lot.
communicative .

He ' s not very

Here you were coming back from your Nobel Prize event and
speaking around the country on autism. Receiving the prize
also meant the beginning of another flood of speaking
activities.

Yes, it was bad. 1 had been doing so many things, 1 got the
flu quite bad in January of 1982. Then 1 got it again the
following year. Too much travelling and being run down. Since
then I've been taking flu shots and I've only had it once. But
I find that flu shots and pneumonia shots are not totally
effective.

Current Work

Riess: Now, today, what are the questions you're still wishing, if you
had time in your lab, you could answer?

Schawlow: I got interested in trying to see these rare earth ions, which
have fairly sharp lines even in solids because they're somewhat
shielded from their neighbors, I wanted to see what they could
tell us about metals, or conducting semi -metals. So I had
students search for these lines. In fact, I just got the proof
of an article that I've written for a memorial issue of
Physica, the Swedish physics magazine, a memorial issue for
George Series.

I start off by saying that he had done some wonderful
things on the details of spectral lines, but there were other
things where you had to look. I said. "There's an old recipe
for rabbit stew that starts, 'First, catch a rabbit.'"
[laughter] In this case, we didn't know where these lines would
be, we had to search. Unfortunately, nobody knows how to
search over a wide range using lasers. They're more like too
sharp a searchlight when you need a flood light.

I would have liked to have taken a laser and studied some
of these lines as they go through the superconducting
transition. The superconductor theorists like Phil Anderson
say this is not very interesting because these ions are not
directly involved in the superconductivity. They have to be
there somehow, but just the copper oxide layer is where the
superconductivity is. That's what they say.

292

Well, I don't think this is the most important thing but
it's interesting, it's a puzzle.

Riess: As it becomes simply less convenient to simply be in your lab,
from parking to the other things that are going on in your
life, do you find yourself becoming more of a theorist?

Schawlow: No, I'll never be a theorist. A theorist is one who can do

mathematical calculations. I can think about the physics, the
theory in broad terms. That's all I can do. I'm not doing
much of that, but I am doing a little of that. I'm trying to
plow through where other people have plowed, and it's not
likely that I'll discover anything worthwhile, but I'm still
intrigued by the puzzles and try to think about them.

Riess: Do you use your computer to get onto the physics websites?

Schawlow: No, not at all. I don't know whether my kind of physics would
be on there. Probably would. I've found some people post
their papers on the net. I haven't tried. I should try for
lasers and nonlocality and things like that.

Riess: I think you should because if anyone can get plugged in, it's
you.

Schawlow: I guess so. You can certainly spend an infinite amount of time
with computers.

[pause]

Schawlow: I've always told my students that to discover something new,
you never have to know everything about a subject, you never
can. All you have to do is recognize one thing that's not
known.

Riess: Charlie Townes said in the introduction to the book in your

honor said that you had a role in the American Physics Society
and other organizations in shaping policy for the world of
physicists. 1

Schawlow: Well, I don't I really had too much to do with it. I was on
the various boards, director of the Optical Society and the
Physical Society, and I was president of each of them. On the
big committees maybe you can nudge things slightly in some
direction- -actually the executive officers, or whatever they're

'p. vii, Lasers, Spectroscopy and New Ideas, A Tribute to Arthur L.
Schawlow, Springer Series in Optical Sciences, 1987.

293

called, executive secretaries, are the people who really run
those things .

Riess: He must be referring to something.

Schawlow: I can't think of anything terribly important, just to try and
keep them on the right path.

I did help to get the Optical Society more deeply into
serious physics. There was one time they had a joint meeting
of the Optical Society and the American Physical Society and I
organized a really high level session on "What is light?" and
got some really top people to give some talks. So, I think I
sort of helped to raise the tone of the Optical Society,
although I certainly didn't do it alone. There were a lot of
other good people.

The Physical Society? I don't know, I gave them whatever
advice I could give, but I don't really think that I changed
the direction appreciably.

Riess: I thought perhaps it might have been vis-a-vis issues in
military or war.

Schawlow: No, I avoided them. I really was bad, I didn't. Most other
presidents have pontificated on such subjects, but not me.

Thinking in Classical Pictures

Riess: You have certainly a reputationand I can tell from this oral
historyas a terrific public speaker. That's a great gift.

Schawlow: I don't know. I gradually gained confidence.

It partly comes back to the way I think. I realize that
even when I was a student that if I had any real ability, it
was that I could look at a subject and say, "Now, what's really
the important thing here? What's it all about? Never mind the
details." And that's a good thing to do when you're trying to
write a presentation, or a paper, or give a talk. If you can
grasp what it's all about, then you can maybe make it clear and
give the illusion to people that they understand it.

I guess I told you I've some horrible experienceswell,
they turned out all right. Like the first time I was invited
to give a talk at the American Physical Society and I was on
the program following Feynman. [laughter]

294
Riess: You really wish to communicate what you are doing, too.

Schawlow: I think so. As I say, I think gradually as you gain

confidence, as you have some success, then you're willing to
stick your neck out and make bolder statements and predictions.

Riess: And somewhere I've written down, "Schawlow has little patience
with abstract theory or tedious mathematical derivations."

Schawlow: That's for sure. As I've sometimes said, I think in fuzzy

pictures. [laughing] I'm not an artist, I can't draw anything,
but I do think in pictures. They are probably not as clear or
sharp as a person with more artistic ability could do, but I
like to picture things.

In some ways, I'm sort of out of step with the world
because I guess I think more in classical pictures. I find
quantum theory very puzzling. Well, everybody agrees it's
puzzling now! But the orthodox view is that there's no use
trying to think of concrete pictures for things you can't
measure like what happens between here and there, when light
is emitted and when it's absorbed. But I keep trying.

Riess: Does fuzzy logic make it more acceptable to think in fuzzy
pictures?

Schawlow: No. Fuzzy logic just means that instead of having things

always off or on, you can adjust them. This is the sort of
thing we've always done as humans. Like when you turn your
radio set on, you set the volume at the level you find
convenient and not always full on or full off. I don't think
there's much more to fuzzy logic than that, except that they're
able to do it in a systematic computer way.

Riess: Do you find chaos theory helpful in thinking about the world?

Schawlow: No. The general idea certainly is true that some things the
image of a butterfly starting a storm--it's true that a lot of
things are easily tipped by a slight initiation one way or the
other. But I don't think that really interacts much with
anything I think about.

A Few Last Stories to Tell

Riess: I want to ask you a question that I don't usually ask, but I'd
like to get it on the record. It's awkward to ask.

295

Schawlow:
Riess:

Schawlow:

Riess:

Schawlow:

That's all right.

What would you like to have gotten out of having done the oral
history?

Well, I thought what I wanted to do was to have a summary of
what I've done so that I could start writing my autobiography
and have the facts down there and try put them into perhaps a
little different shape, with maybe a few more jokes. [laughs]
I mean, I've seen some funny things. But strangely enough, I'm
feeling rather discouraged. I feel that now I've gone through
this stuff, I don't think it's very interesting and I don't
know how I can make myself face it.

I think I've spent too much time trying to cover issues in
physics while you are wishing to tell a more lighthearted
version of your life.

Yes, well, that could easily be done later. I don't know, I
don't think I have the ability to write it, but I'm not sure.
If I ever can get some time to think, I'll have to think about
that. But there just seems to be an endless number of things
that have to be done .

For instance, I got a letter from a lady in Florida who
wants to know if I know a school district in California where
they allow facilitated communication. Well, I don't, but I
can't really say simply that I don't. I'll have to do some
digging and see if I can find something, find somebody that
might know something.

Riess: The autism research has been a secondary field of your life.

Schawlow: Yes, it has. I've had a curiously semi-detached view of

things. What works for me and for Artie is all I care about,
really. But of course you can't really help one person without
helping others. Like he couldn't live by himself, he has to
have a group home, and when I help the group home I help him.
I don't know. Well, I'll call a few people, see if I can get
leads on that one. 1

But there just seems to me an awful lot of stuff. For
instance, I spend a lot of time sorting out my records and CDs,
and then unfortunately getting new ones.

'July 1997, Arthur Schawlow notes that he did find such a school
district in California.

296

Riess: About getting the jokes in, and the lightness, it's hard to
testify to one's own wit and humor.

Schawlow: Yes, well I have a few stale jokes that I keep using over and
over again. Or I don't have jokes, really. I have a spiel
that I use when I break balloons.

There have been some funny things that have happened that I
would like to include if I think of them as I go along, and I
probably have included some. Not necessarily things that I
did. There are some funny things that I've thought up and
which I treasure and sort out. I'll crack jokes and sometimes
they'll fall flat, in which case I won't reuse them.

Riess: In the classroom?

Schawlow: Sometimes. Sometimes in meetings. It's often good to lighten
the meetings. When things get too serious, it helps to have a
little bit of a joke.

Schawlow: Things just occur to me on the spur of the moment. For

instance, there was this talk about "death rays." So I made a
slide from a picture in the encyclopedia of knights in shining
armor and I called it "our laser countermeasures." The shiny
metal would reflect most of the laser light. [laughter]

I was being interviewed by a reporter and I said that as
soon as there were any lasers the science fiction writers, "or
newspaper reporters, as they're sometimes known," thought this
was all for weaponry. [laughter] These things just kind of
come out of the situation.

[tape interruption]

Schawlow:

Riess:

Schawlow:

[Schawlow turns to his music collection] I have a machine that
allows you to scan sheet music into it and transpose it and
print it out in a different key. For clarinet, you know, you
can take piano things and transpose them. If I ever do play
the clarinet again. Right now it's just kind of speculation.

Do you think you will get back to the clarinet? It might be
good for your lungs .

I don't really know. That's what the physical therapist said,
I really ought to do it, for my lungs. I do a lot of just kind
of sitting, staring at newspapers and magazines, things like
that. I don't have a lot of energy. But I'm getting better.

297

[Schawlow puts on a CD] I got this record--! used to go to
New York several times a year and I would go, always, to Jimmy
Ryan's, where usually Joe Muranyi was playing clarinet. He's
Hungarian descent and speaks the Hungarian language and in
recent years has been going back and forth to Hungary where
he's a big hero as a jazzman who played with Louis Armstrong.

[tape interruption]

Schawlow: [ Schawlow reviews with Riess the spelling of the names of some
Chinese physicists] Before we went to China we took a short
course in Chinese in night school run by Foothill Junior
College in Palo Alto. In China, everywhere we were we went to
a Friendship Store. They have souvenirs and things. I would
tell my wife "Wode chyan bugou"--my money's not enough,
[laughter]

The course was taught by a nice old Chinese gentleman, Dr.
P.F. Tao, who had gotten a Ph.D. in Berlin many years before.
I liked that course so much that I thought, two years later,
I'd go back and take a little more.

Anyway, then we came across the word "chang" meaning "to
sing," and also the word "chang" meaning "often." So I asked
Mrs. Xia, who was then visiting in our lab, "How do you say,
'We often sing Chinese songs?'" And she said, "Women tsang
tsang jungwo ger." I told the teacher this and he said, "Oh
yes, that's the Shanghai dialect." [laughter] Apparently the
dialect all the way through the middle of China is something
like that because people in Chungking were doing that too.

When we were in China it was interesting listening to
people on the street. We could occasionally make out a word.
I really had very little vocabulary and we had not studied
characters at all. In this night school Chinese class there
were several people of Chinese origin, but they spoke Cantonese
and they wanted to learn to speak Mandarin.

That second attempt to learn Chinese came in the autumn of
1981. In October I learned that I had to make the trip to
Stockholm for the Nobel Prize and I had many new things to get
done. So I went back to the class the next week and told Dr.
Tao that I couldn't continue with the course. He said, "We
understand, and we're greatly honored to have you. We would
like to put on a banquet in your honor."

So, two or three weeks later they had a banquet at a local
Chinese restaurant. It was attended by that class and another,
and there was an orchestra of students playing Chinese musical
instruments. A student reporter for the Foothill Junior

Riess:

Schawlow:

298

College newspaper was present at the event. A couple of weeks
after that, an article appeared with the heading, "Foothill
Dropout Honored for Nobel Prize." [laughter]

The main trouble with learning to speak a foreign language
is that when you say something, then they answer you, and then
you're lost. You can carefully compose a sentence, but you
never know what's going to happen.

Did I tell you about my encounter with Italian?

We were in Florence. My wife, who had studied some
Italian--! had not, although I had listened to a record of
Italian phrases insisted that I buy the tickets to Rome. So I
went up to the counter--! had carefully preparedand I said,
"Due bigletti per Roma, primo classe, con posti reservati"
"two tickets to Rome first class with reserved seats." I had
the time written down on a piece of paper.

He said, "Si, oggi?" And I had no idea what he meant.
Then he said, "Today?" [laughter] A perfect example of where
you can get thrown by lack of vocabulary.

Professor Schawlow, here is where the interview ends. 1 Are you
content with our linguistic discussion as the final note? Or
do you want to sum up in some way, as if you knew that you were
having a last say?

[written addition] Well, I always told my students that there
are three rules for writing: (1) have something to say (that's
the hardest part), (2) say it, and (3) stop.

However, looking back, I have had some success and a lot of
satisfaction in life. It has been hard work, and I have
stupidly overlooked some good things that I might have found.
Perhaps my focus was too narrow at times, but I felt that I had
to concentrate on what seemed most important and yet
attainable. The only fact that saved me was that others
overlook things, and so, as I told my students, there are still
lots of simple and beautiful things to be discovered. I really
believe that.

I did have some wonderful research collaborators and
students, and they helped to make up for my deficiencies.
Science is cumulative and many very able people have taken up
some of my work, and carried it far beyond anything I imagined.

J This final question to Arthur Schawlow was added and answered in the
editing stage, after the interviews were concluded.

299

Thus, while some of my results are properly forgotten, others
have gone so far as to make me look a lot more prescient than I
ever was. In all, physics has been intriguing, at times
frustrating and compelling, but very worthwhile. I can't
imagine doing anything else with my life.

Transcriber: Lisa Vasquez
Final Typist: Caroline Sears

300

TAPE GUIDE --Arthur Schawlow

Interview 1: August 14, 1996

Tape 1, Side A

Tape 1, Side B

Tape 2, Side A

Tape 2, Side B

Interview 2: August 21, 1996
Tape 3, Side A
Tape 3, Side B
Tape 4, Side A
Tape 4, Side B

Interview 3
Tape 5
Tape 5
Tape 6

September 4, 1996
Side A
Side B
Side A

Tape 6, Side B

Interview 4:
Tape 7,
Tape 7
Tape 8

September 12, 1996
Side A
Side B
Side A

Tape 8, Side B

Interview 5: October 30, 1996
Tape 9, Side A
Tape 9, Side B
Tape 10, Side A
Tape 10, Side B
Insert from Tape 12, Side A
Insert from Tape 12, Side B
Insert from Tape 13, Side B
Insert from Tape 14, Side A

Interview 6: November 7, 1996

Tape 11, Side A

Tape 11, Side B

Tape 12, Side A

Interview 7: November 14,
Tape 13, Side A
Tape 13, Side B
Tape 14, Side B

1996

1
?

19
28

38
48
57
72

106

115
124
132
142

150
159
169
180
188
191
200
201

209
218
226

233
241
251

Interview 8: November 26, 1996

301

Tape 15, Side A 263

Tape 15, Side B 271

Tape 16, Side A 280

Tape 16, Side B

Tape 17, Side A 296

Tape 17, Side B not recorded

APPENDIX

A Publications 302

B Four pages excerpted from Toronto Jazz, A Survey of Live

Appearances and Radio Broadcasts of Dixieland Jazz Experienced in
Toronto During the Period 1948-1950, by Jack Litchfield. 316a

C "From Maser to Laser", by Arthur L. Schawlow, in Impact of Basic

Research on Technology, Kursunoglu and Perlmutter, editors, Plenum
Press, New York-London, 1973. 317

D "Masers and Lasers", by Arthur L. Schawlow, Fellow, Institute of
Electrical and Electronics Engineers, from IEEE Transactions on
Electron Devices, Vol. ED-23, No. 7, July 1976. 354

E "Never Too Late, Communication With Autistic Adults", by Aurelia
T. Schawlow and Arthur L. Schawlow, in Proceedings of the NSAC
(now Autism Society of America) National Conference, July 1985. 361

302 APPENDIX A

Publications by ARTHUR L. SCHAWLOW

1. Nuclear Moments of Silver (M.F. Crawford, ALS, W.M. Gray, and F.M. Kelly),

Phys. Rev. 75, 1112 (1949) (letter).

2. Transmission and Reflection Coefficients of Aluminum Films for

Interferometry (M.F. Crawford, W.M. Gray, ALS, and F.M. Kelly),
J. Opt. Soc. Am. 39, 888 (1949).

3. Electron-Nuclear Potential Fields from Hyperfine Structure (M.F. Crawford

and ALS), Phys. Rev. 76, 1310, (1949).

4. Nuclear Moments of 25 Mg (M.F. Crawford, F.M. Kelly, ALS, and W.M. Gray),

Phys. Rev. 76, 1527 (1949) (letter).

5. Hyperfine Structure and Nuclear Moments of 207 Pb (ALS, J.N.P. Hume,

and M.F. Crawford), Phys. Rev. 76, 1876 (1949) (letter).

6. Isotope Shift in the Resonance Lines of Zinc (M.F. Crawford, W.M. Gray,

F.M. Kelly, and ALS), Can. J. Res., A, 28, 138 (1950).

7. An Atomic Beam Source and Spectrograph for Hyperfine Structure. Nuclear

Moments of Silver (M.F. Crawford, ALS, F.M. Kelly, and W.M. Gray),
Can. J. Res., A, 28, 558 (1950).

8. Nuclear Magnetic Moments and Similarity between Neutron and Proton States

in the Nucleus (ALS and C.H. Townes), Phys. Rev. 82, 268 (1951)
(letter) .

9. Significance of the Results of Microwave Spectroscopy for Nuclear Theory,

Ann. New York Acad. Sci . 35, 955 (1952).

10. Microwave Spectrum and Structure of Re0 3 Cl (E. Amble, S.L. Miller, ALS,

and C.H. Townes), J. Chem. Phys. 20, 192 (1952).

11. Charge Distribution in Nuclei from X-Ray Fine Structure (ALS and

C.H. Townes) , Science, 115, 284 (1952).

12. Quadrupole Coupling Ratio of the Chlorine Isotopes (T.C. Wang, C.H.

Townes, ALS, andA.N. Holden) , Phys. Rev. 86, 809 (1952) (letter).

13. A Microwave Spectrum of the Free OH Radical (T.M. Sanders, Jr., ALS,

G.C. Dousmanis, and C.H. Townes), J. Chem. Phys. 22, 245 (1954).

14. Examination of Methods for Detecting OH (T.M. Sanders, Jr., ALS, G.C.

Dousmanis, and C.H. Townes), J. Chem. Phys. 22, 245 (1954).

15. Hyperfine Structure in the Spectrum of N 14 H 3 . I. Experimental Results

(G.R. Gunther-Mohr, R.L. White, ALS, W.E. Good, and D.K. Coles),
Phys. Rev. 94, 1184 (1954).

16. Nuclear Quadrupole Resonances in Solid Bromine and Iodine Compounds,

J. Chem. Phys. 22, 1211 (1954).

303

17. Structure of the Intermediate State in Superconductors (ALS, B.T.

Matthias, H.W. Lewis, and G.E. Devlin), Phys . Rev. Letters 95, 1344
(1954) .

18. Effect on X-Ray Fine Structure of Deviations from a Coulomb Field near

the Nucleus (ALS and C.H. Townes), Phys. Rev. 100, 1273 (1955).

19. Microwave Spectroscopy (C.H. Townes and ALS), McGraw-HillBook Company,

New York (1955). (Reprinted by Dover Publication 1975).

20. Structure of the Intermediate State in Superconductors, in Proceedings

of the Conference de Physique des Basses Temperatures, CNRS,
Paris 1955.

21. Crystal Structure and Quadrupole Coupling of Cyanogen Bromide, BrCN

(S. Geller and ALS), J. Chem. Phys. 23, 779 (1955).

22. Structure of the Intermediate State in Superconductors, Phys. Rev.

101, 573 (1956).

23. Intermediate State Of Superconductors: Influence of Crystal Structure

(ALS and G.E. Devlin), Phys. Rev. 110, 1011 (1958).

24. Structure of the Intermediate State of Superconductors (ALS and G.E.

Devlin), in Proceedings of the Fifth International Conference on

Low Temperature Physics and Chemistry, Madison, Wisconsin, 1957, J.R.

Dillinger, ed., University of Wisconsin Press (1958), p. 311.

25. Penetration of Magnetic Fields through Superconducting Films, Phys. Rev.

Letters 109, 1856 (1958).

26. Infrared and Optical Masers (ALS and C.H. Townes), Phys. Rev. 112, 1940

(1958) .

27. Effect of the Energy Gap on the Penetration Depth of Superconductors (ALS

and G.E. Devlin), Phys. Rev. 113, 120 (1959).

28. Structure-Sensitivity of the High-Frequency NMR in Powdered

Anntiferromagnetic MnF 2 (J.L. Davis, G.E. Devlin, V. Jaccarino, and
ALS), J. Phys. Chem. Solids 10, 106 (1959).

29. Superconductivity, in Experimental Methods in Physics, Academic Press,

New York (1959), Vol. 6, p. 71.

30. Intermediate State of Hard Superconductors (ALS, G.E. Devlin, and J.K.

Hulm) , Phys. Rev. 116, 626 (1959).

31. Electronic Spectra of Exchange-Coupled Ion Pairs in Crystals (ALS, D.L.

Wood, and A.M. Clogston) , Phys. Rev. Letters 3, 271 (1959).

32. Optical Detection of Paramagnetic Resonance in an Excited State of Cr 3 *

in A1 2 3 (S. Geschwind, R.J. Collins, and ALS), Phys. Rev. Letters
3, 545 (1959) .

33. Self-Absorption and Trapping of Sharp-Line Resonance Radiation in Ruby

(F. Varsanyi, D.L. Wood, and ALS), Phys. Rev. Letters 3, 544 (1959).

304

34. Optical Detection of Paramagnetic Resonance in Crystals at Low Temperature

(J. Brosset. S. Geschwind, and ALS), Phys . Rev. Letters 3, 548
(1959) .

35. Infrared and Optical Masers, in Quantum Electronics, Columbia University

Press, New York (1960), p. 553.

36. Coherence, Narrowing, Directionality, and Relaxation Oscillations in the

Light Emission from Ruby (R.J. Collins, D.F. Nelson, ALS, W.Bond,
C.G.B. Garett, and W. Kaiser), Phys. Rev. Letters 3 (1960).

37. Infrared and Optical Masers, Bell Laboratories Record 38, 403 (1960).
37A. Infrared and Optical Masers, J. Am. Soc. Naval Engrs . 73, 45 (1961).

38. Optical Masers, Northeast Electronics Research & Engineering Record,

158 (1960).

39. Zeeman Effect of the Purely Cubic Field Fluorescence Line MgO:Cr 3 *

Crystals (S. Sugano, ALS, and F. Varsanyi), Phys. Rev. 120, 2045
(1960) .

40. Corbino Disk (D.A. Kleinman and ALS) , J. Appl. Phys. 31, 276 (1960).

41. Simultaneous Optical Maser Action in Two Ruby Satellite Lines (ALS

and G.E. Devlin), Phys. Rev. Letters 6, 96 (1961).

42. Nuclear Quadrupole Resonance in an Antiferromagnet (J.C. Burgiel,

V. Jaccarino, and ALS), Phys. Rev. 122, 429 (1961).

43. Strain-Induced Effects on the Degenerate Spectral Line of Chromium in

MgO Crystals (ALS, A.H. Piksis, and S. Sugano), Phys. Rev. 122,
1469 (1961) .

44. Infrared and Optical Masers, Sol. St. J. 2, 21 (1961).

45. Optical Masers, Sci. Am. 204, 52 (1961).

45A. Optical Masers, Usp. Fiz. Nauk. 75, 569 (1961).

45B. Optical Masers, in Akceleratory, Reaktory, Lasery, Panstwowe Wydawnictwo
Naudowe, Warsaw (1964). (Reprinted).

46. Fine Structure and Properties of Chromium Fluorescence in Aluminum and

Magnesium Oxide, in Advances in Quantum Electronics, J.R. Singer,
ed., Columbia University Press, New York (1961), p. 50.

47. Composite Rod Optical Maser (G.E. Devlin, J. McKenna, A.D. May, and ALS),

Appl. Opt. 1, 11 (1962) .

48. Fine-line Spectra of Chromium Ions in Crystals, J. Appl. Phys.

Suppl. 33, 395 (1962).

49. Masers, in Collier's Encyclopedia (1962), p. 493.

49A. Masers, Electro-Technology, J. Soc. Elec. Engr., Electronics and Radar
Development Establishment, Bangalore, 6, 199 (1962) . (Reprinted) .

305

50. Lasers, Encyclopedia of Science and Technology, McGraw-Hill Book

Company, New York (revised-1969) , p. 406 a-d.

50A. Optical Masers (P. Kisliuk and ALS) , in McGraw-Hill Encyclopedia of

Science and Technology Yearbook, McGraw-Hill Book Company, New York
(1962) . p. 380.

51. Optical Masers, in Proceedings of 1961 London Conference on Optical

Instruments and Techniques, K.J. Habell, ed., Chapman and Hall,
London {1962} . p. 431.

52. Coherent Light for Communications, in Proceedings of the Symposium on

Tracking and Command of Aerospace Vehicles, Institute of Aerospace
Sciences, New York (1962) .

53. Tilted Plate Interferometry with Large Plate Separations (H.W. Moos,

G.F. Imbusch, L.F. Mollenauer, and ALS) , Appl . Opt. 2, 817 (1963).

54. Optical Masers (Lasers), (ALS and H.W. Moos), in McGraw-Hill Encyclopedia

of Science and Technology Yearbook, McGraw-Hill Book Company,
New York (1963) .

55. Crystals and Light, Stanford Research Inst. J. 6, 3 (1962).

56. Widths and Positions of Sharp Optical Lines in Solids, in Quantum

Electronics III, Proceedings of the Third International Conference,
Paris, 1963, P. Grivet and N. Bloembergen, eds ., Columbia
University Press, New York (1964), p. 645.

57. Energy Levels in Concentrated Ruby (P. Kisliuk, ALS, and M.D. Sturge) , in

Quantum Electronics III, Proceedings of the Third International
Conference, Paris, 1963, P. Grivet and N. Bloembergen, eds.,
Columbia University Press, New York (1964), p. 51.

58. The High Gain Laser as a Wavelength Standard (L.F. Mollenauer, G.F.

Imbusch, H.W. Moos, ALS, and A.D. May), in Proceedings of the
Symposium on Optical Masers, Polytechnic Institute of Brooklyn, April
16-19, 1963, J. Fox, ed., Polytechnic Press, Brooklyn, New York
(1963), p. 51.

59. Enhanced Ultraviolet Output from Double-Pulsed Flash Lamps (J.L. Emmett

and ALS), Appl. Phys . Letters 2, 204 (1963).

60. Advances in Optical Masers, Sci . Am. 209, 34 (1963).

60A. Advances in Optical Masers, Usp. Fiz. Nauk 81, 745 (1963) . (Reprinted)

60B. Advances in Optical Masers, abridged translation "Le Applicazioni
Pratiche del Laser" (Sapere, no. 650, p. 102 ((1964).

61. Optical and Infrared Masers, Contemp. Phys. 5, 81 (1963).

62. Temperature Dependence of the Width and Position of the 2 E- 4 A 2

Fluorescent Lines of Cr 3 * and V 2 * in MgO (G.F. Imbusch, W.M.

Yen, ALS, D.E. McCumber, and M.D. Sturgge) , Phys. Rev. 133, A1029

(1964) .

306

63. Optically Pumped K-.-. ~ers and Solid State Masers, in Proceedings of the

International School of Physics "Enrico Fermi," Course XXXI,
Quantum Electronics and Coherent Light, Varenna, Italy, 1963,
P. A. Miles, ed., Academic Press, New York (1964).

64. Lasers and Coherent Light, Phys . Today 17, 28 (1964).

65. Direct Measurement of Xenon Flashtube Opacity (J.L. Emmett, ALS, E.H.

Weinberg), J. Appl . Phys. 35, 2601 (1964).

6t . Phonon-Induced Relaxation in Excited Optical States of Trivalent

Praseodymium in LaF 3 (W.M. Yen, W.C. Scott , and ALS), Phys. Rev.
136, A271 (1964) .

67. Isotope Shifts in the R Lines of Chromium in Ruby and MgO (G.F. Imbusch

W.M. Yen, ALS, G.E. Devlin, and J.P. Remeika) , Phys. Rev. 136, A271

(1964) .

68. A Portable Demonstration Laser (K.H. Sherwin and ALS), July, 1964,

(Not for publication) .

68A. How the Ruby Laser Works, Popular Science, November 1964, taken in part
from "A Portable Demonstration Laser."

69. Fluorescence of MgO:Cr 3 * Ions in Non-Cubic Sites (G.F. Imbusch, ALS,

A.D. May, and S. Sugano) , Phys. Rev. 140, A830 (1965).

70. Lasers, Science 149, 13 (1965).

71. Lasers (H.G. Freie and ALS), in Advanced Optical Techniques, A.C.S. van

Heel, ed., North-Holland Publishing Company (1967), p. 467.

72. Measuring the Wavelength of Light with a Ruler, Am. J. Phys. 33, 922,

(1965) .

73. Observation of a Spin Wave Sideband in the Optical Spectrum of MnF 2

(R.L. Greene, D.D. Sell, W.M. Yen, ALS, and R.M. White), Phys. Rev.
Letters 15, 656 (1965) .

74. Lasers, in the Symposium in International Ophthalmology Clinics (A

Quarterly Book Series), Little, Brown and Company (1966), 6, No. 2,
p. 241.

75. Effect of Ultraviolet Pumping on Ruby Laser Output (R.L. Greene, J.L.

Emmett, and ALS), Appl. Opt. 5, 350 (1966).

76. Magnetic Effects in the Optical Spectrum of MnF 2 (D.D. Sell, R.L. Greene,

W.M. Yen, ALS, and R.M. White) in Proceedings of the Conference on
Magnetism and Magnetic Materials, 1965, in J. Appl. Phys. 37, 1229

(1966) .

77. Beam of the Future, in Science Year, The World Book Science Annual 1965,

Field Enterprises Education Corporation (1965), p. 167.

307

78. Far Infrared Spectra of V 4+ and Co 2 * Single Ions in Corundum (J. Y. Wong,

M. J. Berggren, and ALS) ) , in Proceedings of the Conference on
Optical Properties of Ions in Crystals, 1966, H. M. Crosswhite and H.
W. Moos, eds . , Interscience Publishers, New York (1967), p. 383.

79. Far Infrared Spectra of Al 2 3 :Ti 3+ ( E. D. Nelson, J. Y. Wong,

andALS), Phys . Rev. 156, 298 (1967).

80. Far Infrared Spectra of Al 2 3 :Cr 3+ and Al 2 3 :Ti 3+ ( E. D. Nelson, J. Y.

Wong, and ALS), in Proceedings of the Conference on Optical
Properties of Ions in Crystals, 1966, H. M. Crosswhite and H. W.
Moos, eds ., Interscience Publishers, New York (1967), p. 375.

81. Thermal Shifts in the Energy Levels of LaF 3 :Nd 3+ (S.A. Johnson, H.G.

Freie, ALS, and W.M. Yen), J. Opt. Soc. Am. 57, 734 (1967).

82. Spontaneous Emission from a Helium-Neon Laser as a Convenient Wavelength

Standard (J.L. Rapier, H.H. Heimple, andALS), Am. J. Phys. 35, 890
(1967) .

83. Selective Laser Photocatalysis of Bromine Reactions (W.B. Tiffany, H.W.

Moos, andALS), Sci. 157, 40 (1967).

84. Piezospectroscopic Studies of Exchange-Coupled Cr 3 * Ion Pairs in Ruby

(L.F. Mollenauer andALS), Phys. Rev. 168, 309 (1968).

85. Lasers and Coherent Light, Am. Sci. 55, 197 (1967).

86. Transverse Stimulated Emission in Liquids (J.L. Emmett and ALS),

Phys. Rev. 170, 358 (1968).

87. Far Infrared Spectrum of A1 2 3 :V 4+ (J.Y. Wong, M.J. Berggren, and ALS),

J. Chem. Phys. 49, 835 (1968).

88. Spectroscopic Studies of SrTi0 3 Using Impurity Ion Probes (S.E. Stokowski

andALS), Phys. Rev. 178, 457 (1969).

89. Laser Light, Sci. Am. 219, 120 (1968).

90. Dielectric-Related Optical Line Shifts in SrTi0 3 :Cr 3+ (S.E. Stokowski

andALS), Phys. Rev. 178, 464 (1969).

91. Electric-Field Effects on the Spectrum of Chromium in Strontium Titanate

(S.E. Stokowski andALS), Phys. Rev. Letters 21, 965 (1968).

92. Lasers and Light, readings from Scientific American, with Introductions

by A.L. Schawlow, W.H. Freeman and Company, Incorporated,
San Francisco (1969) .

93. Plasma Refractive Effects in HCN Lasers (B.W. McCaul and ALS), in

Proceedings of the Second Conference on Lasers, Annals of the
New York Academy of Sciences 168, 3 (1970), p. 697.

308

94. Lasers and Their Light, in Laser Photocoagulation and Retinal Angiography,

by H.C. Zweng, H.L. Little, and R.B. Peabody, The C.V. Mosby
Company, Saint Louis (1969), p. 3.

95. Design and Analysis of Flashlamp Systems for Pumping Organic Dye Lasers

(J.F. Holzrichter and ALS), in Proceedings of the Second Conference
on Lasers, Annals of the New York Academy of Sciences 168, 3
(1970), p. 703.

96. Is Your Research Moral? Physics Today 22, 118 (1969).

97. Lasers: The Old Dream and the New Reality, preface for book on Laser

Applications, by W.V. Smith, Artech House, Incorporated (1970) .

98. Polarized Fluorescence Study of Cr 3+ Through a Stress-Induced Phase

Transition in SrTi0 3 (T.S. Chang, J.F. Holzrichter, G.F. Imbusch,
and ALS), Sol. St. Comm. 8, 1179 (1970).

99. Direct Observation of Single-Domain SrTi0 3 (T.S. Chang, J.F. Holzrichter,

G.F. Imbusch, and ALS) , Appl . Phys. Letters 17, 6 (1970).

100. Depolarized Light Scattering from Liquid Bromine (M.D. Levenson and ALS),

Opt. Comm. 2, 4 (1970) .

101. Cubic to Trigonal Stress Induced Phase Transition in SrTi0 3 (L.S. Wall,

M. Rokni, and ALS), Sol. St. Comm. 9, 573 (1971).

102. Laser Action of Dyes in Gelatin (T.W. Hansch, M. Pernier, and ALS),

IEEE J. Quant. Electr. QE-7, 45 (1971).

103. Dispersion in C 6 H 6 and C 6 D 6 (M.S. Sorem and ALS), Phys. Letters 33A, 268

(1970) .

104. Image Amplification by Dye Lasers (T.W. Hansch, F. Varsanyi, and ALS),

Appl. Phys. Letters 18, 108 (1971).

105. Complete Hyperfine Structure of a Molecular Iodine Line (T.W. Hansch,

M.D. Levenson, and ALS), Phys. Rev. Letters 26, 946 (1971).

106. Magnetization Induced by Optical Pumping in Antiferromagnetic *MnF 2

(J.F. Holzrichter, R.M. Macfarlane, and ALS), Phys. Rev. Letters 26,
652 (1971).

107. An Image Orthicon Spectrograph with Computer Control (S.A. Johnson,

W.M. Fairbank Jr., and ALS), Appl. Opt. 10, 2259 (1971).

108. High Resolution Saturation Spectroscopy of the Sodium D Lines with a

Pulsed Tunable Dye Laser (T.W. Hansch, I.S. Shahin and ALS), Phys.
Rev. Letters 27, 707 (1971).

109. From Maser to Laser, in The Impact of Basic Research on Technology,

B. Kursunoglu and A. Perlmutter, eds., Plenum Press (1973), p. 113.

309

110. Saturation Spectroscopy of Molecular londine Using the 5017A Argon

Laser Line (M.S. Sorem, M.D. Levenson, and ALS) , Phys . Letters 37A,
33 (1971).

111. Spectroscopy with Tunable Lasers in the Visible Region, in Proceedings

of the Esfahan Symposium on Fundamental and Applied Laser Physics,
Esfahan, Iran, August /September 1971.

112. Measurements of the Kinetic Energy of Free Positronium Formed in MgO

(S. M. Curry and ALS), Phys. Letters 37A, 5 (1971).

113. Lasers: The Light Fantastic, in Physical Science Today, Communications

Research Machines, Incorporated (1973), p. 523.

114. Optical Resolution of the Lamb Shift in Atomic Hydrogen by Laser

Saturation Spectroscopy (T. W. Hansch, I. S. Shahin, and ALS), Nature
235, 63(1972).

115. Hyperfine Interaction in Molecular Iodine (M. D. Levenson and ALS),

Phys. Rev. A6, 10 (1972).

116. Saturation Spectroscopy in Molecular Iodine by Intermodulated Fluorescence

(M. S. Sorem and ALS), Opt. Comm. 5, 148 (1972).

117. Ultrasensitive Response of a CW Dye Laser to Selective Extinction

(T. W. Hansch, ALS, P. E. Toschek) , IEEE J. Quant. Electr. QE8, 802
(1972) .

118. Nuclear Quadrupole Coupling of the 1 Z +9 and 2IT Du States of Molecular

Iodine (M. S. Sorem, T. W. Hansch, and ALS), Chem. Phys. Letters 17,
300(1972) .

119. Simple Dye Laser Repetitively Pumped by a Xenon Ion Laser (T. W. Hansch,

ALS, and P. Toschek), IEEE J. Quant. Electr. QE-9, 553 (1973).

120. Lasers - Present and Future, in Proceedings of the Royal Institution,

1973, England, February 16, 1973.

121. Hyperfine Quantum Beats Observed in Cs Vapor under Pulsed Dye Laser

Excitation (S. Haroche, J. A. Paisner, and ALS), Phys. Rev. Letters
30, 948 (1973).

122. Measuring the Diameter of a Hair by Diffraction (S. M. Curry and ALS),

Am. J. Phys. 42, 412 (1974).

123. The Better To See..., in The Greatest Adventure, E. H. Kone and

H. J. Jordan, eds . , Rockefeller University Press (1974), p. 176.

124. Two-photon Spectroscopy of Na 3s - 4d Without Doppler Broadening using

a CW Dye Laser (T. W. Hansch, K. C. Harvey, G. Meisel, and ALS),
Opt. Comm. 11, 50 (1974) .

125. Lasers and Masers, in Encyclopedia Britannica (1974), p. 686.

126. Observation of Zeeman Quantum Beats in Molecular Iodine (R. Wallenstein,

J. A. Paisner, and ALS) , Phys. Rev. Letters 32, 1333 (1974).

310

127. Isotope Separation by Selective Unimolecular Photoisomerization

(J. I. Brauman, T. J. O'Leary, and ALS) , Opt. Comm. 12, 223 (1974).

128. Absolute Measurement of Very Low Sodium Vapor Densities Using Laser

Resonance Fluorescence (W. M. Fairbank, Jr., T. W. Hansch, and ALS),
J. Opt. Soc. Am. 65, 199 (1975).

129. Excited State Absorption in Ruby, Emerld, and MgO: Cr 3+ (W. M. Fairbank,

Jr., G. K. Klauminzer, and ALS) , Phys . Rev. 11, B60 (1975).

130. Cooling of Gases by Laser Radiation (T. W. Hansch and ALS) Opt. Comm.

13, 68 (1975).

131. Measurement of the Stark Effect in Sodium by Two-Photon Spectroscopy

(K. C. Harvey, R. T. Hawkins, G. Meisel, and ALS), Phys. Rev. Letters
34, 1073 (1975).

132. Masers and Lasers, IEEE Electr. Devices, ED-23, 773 (1976).

133. Identification of Absorption Lines by Modulated Lower-Level Population:

Spectrum of Na 2 (M. E. Kaminsky, R. T. Hawkins, F. V. Kowalski, and
ALS), Phys. Rev. Letters 36, 671 (1976).

134. Simplification of Spectra by Polarization Labeling (R. Teets,

R. Feinberg, T. W. Hansch, and ALS), Phys. Rev. Letters
37, 683 (1976) .

135. Digital Wavemeter for C.W. Lasers (F. V. Kowalski, R. T. Hawkins,

and ALS), J. Opt. Soc. Am. 66, 965 (1976).

136. Lasers, in Science Technology, and the Modern Navy, Thirtieth Anniversary

1946-1976, Office of Naval Research, Arlington, Virginia (1976) .

137. Ground State Relaxation Measurements by Laser-Induced Depopulation

(R. Feinberg, R.E. Teets, J. Rubbmark, and ALS), J. Chem. Phys.

66, 4330 (1977).

138. Stark Effect Study of Excited States in Sodium Using Two-Photon

Spectroscopy (R.T. Hawkins, W.T.Hill, F.V. Kowalski, ALS, and
S.Svanberg), Phys. Rev. A15, 967 (1977).

139. Lasers, Light and Matter, Frederic Ives Medal Address, J. Opt. Soc. Am.

67, 140 (1977).

140. Laser Interactions with Materials, in Proceedings of the LASER-77

Opto-Electronic Conference, June 21-24, 1977, Munich, Germany
(in press) .

141. Saturated-Interference Spectroscopy (F.V. Kowalski, W.T.Hill, and ALS),

Optics Letters 2, 112 (1978).

142. An Improved Wavemeter for CW Lasers (F.V. Kowalski, R.E. Teets,

W.Demtroder, and ALS), J. Opt. Soc. Am. 68, 1611 (1978).

311

143. Twenty Years of Laser Physics (ALS), in Proceedings of LASER-78

International Conference Mount Royal Hotel: London, 9-10 March
(1978) .

144. Laser Spectroscopy of Atoms and Molecules, Science 202, (1978), pp. 141-7.

145. The Spectrum of Atomic Hydrogen (T.W. Hansch, G.W. Series, and ALS),

Scientific American 240, No. 3, 94(1979)

146. Polarization Labeling Spectroscopy of N0 2 , (R.E.Teets, N.W.Carlson, and

ALS), J. Molec. Spectro., 78, 415 (1979).

147. Doppler-Free Intermodulated Opto-Galvanic Spectroscopy (J.E.Lawler,

A.I.Ferguson, J.E.M. Goldsmith, D.J.Jackson, and ALS), Physical
Review Letters, 42, 1046 (1979).

148. Precision Interferometer Calibration Technique for Wavelength

Measurements: Iodine Wavelengths at 633 nm and H (J.E.M. Goldsmith,
E.W.Weber, F. V. Kowalski, and ALS), Appl . Opt. 18, 1983 (1979).

149. Identification of Excited States in Na 2 by Two-Step Polarization Labeling

(N.W.Carlson, F.V. Kowalski, R.E.Teets, and ALS), Opt. Comm. 29, 302
(1979) .

150. Lasers: The Practical and the Possible, Stanford Magazine 7, 24 (1979).

151. Doppler-Free Two-Photon Optogalvanic Spectroscopy (J.E.M. Goldsmith,

A.I.Ferguson, J.E.Lawler, and ALS) , Optics Letters 4, 230 (1979).

152. Doppler-Free Optogalvanic Spectroscopy (J.E.Lawler, A.I.Ferguson,

J.E.M. Goldsmith, D.J.Jackson, and ALS), in Proceedings of the Fourth
International Conference on Laser Spectroscopy, June 11-14, 1979,
Garching, West Germany.

153. Some Methods of Laser Spectroscopy, in Proceedings of the International

Conference on the Physics of Electronics and Atomic Collisions,
IPEAC 1979, N.Oda and K.Takayanagi, eds., Aug. 29-Sept. 4, 1979,
Kyoto, Japan.

154. The Laser Revolution, in Proceedings of the Fourth National Quantum

Electronics Conference, Sept. 19-21, 1979, Edinburgh, Scotland.

155. Sensitive Intracavity Absorption At Reduced Pressures (W. T. Hill III,

R.A. Abreu, T.W. Hansch and A.L.S.), Optics Comm. 32, 96 (1980).

156. Superradiance Triggering Spectroscopy (N.W. Carlson, D.J. Jackson,

A.L.S., M. Gross and S. Haroche) , Optics Comm. 32, 350 (1980).

157. Identification of Rydberg States in Na 2 , by Two-Step Polarization

Labeling (N.W. Carlson, A.J. Taylor, and A.L.S.), Phys . Rev. Lett.
45, 18 (1980).

158. Polarization Intermodulated Excitation (POLINEX) Spectroscopy

of Helium and Neon (T.W. Hansch, D.R. Lyons, ALS, A. Siegel,
A-Y. Wang, and G-Y. Yan, Opt. Comm. 37, 87 (1981).

312

159. Two-Step Polarization Labeling of Excited States of Na 2 (N.W. Carlson,

A.J. Taylor, K.M. Jones, and ALS) , Phys. Rev. A24, 822 (1981)

160. Doppler-Free Radiofrequency Optogalvanic Spectroscopy (D.R. Lyons,

ALS, and G-Y. Yan) , Opt. Comm. 38, 35 (1981).

161. A Study of the Excited 1 Z* 9 States in Na 2 (A.J. Taylor, K.M. Jones,

andALS), Opt. Comm. 39, 47 (1981).

162. Two-Photon Line Shapes with Near-Resonant Enhancement (H-R. Xia,

G-Y. Yan, andALS), Opt. Comm. 39, 153 (1981).

163. Selective Spectrum Simplification by Laser Level Labeling

(N.W. Carlson, K.M. Jones, G.P. Morgan, ALS, A.J. Taylor, H-R. Xia,
and G-Y Yan) , in Laser Spectroscopy V, Proceedings of the V
Conference on Laser Spectroscopy, A.R. McKellar, T. Oka, and B.P.
Stoicheff, eds., Springer-Verlag, New York (1981), p. 51.

164. Polarization Intermodulated Excitation (POLINEX) Spectroscopy

of Excited Atoms (Ph. Dabkiewicz, T.W. Hansch, D.R. Lyons,

ALS, A. Siegel, Z-Y. Wang, and G-Y. Yan), in Laser Spectroscopy V,

Proceedings of the V Conference on Laser Spectroscopy,

A.R. McKellar, T. Oka, and B. P. Stoicheff, eds. Springer-Verlag,

New York (1981) , p. 178.

165. Spectral Structure of Continuous-Wave Two-Photon Transitions

in Na (G.P. Morgan, H-R. Xia, and ALS), J. Opt. Soc. Am.
72, 315 (1982).

166. A Multiple-Wedge Wavemeter for Pulsed Lasers, (L.-S. Lee, and ALS),

Optics Letters 6, 610 (1981).

167. Simplifying Spectra by Laser Level Labeling, in the Proceedings of

the International Colloquium on Molecular Spectroscopy,
Stockholm, Sweden, May 11-15, 1981, also Physica Sripta
25, 333 (1982).

168. Spectroscopy in a New Light, Nobel Prize Lecture, in Les Prix Nobel,

Nobel Foundation, Stockholm, 1982,

168A Spectroscopy in a New Light, Reviews of Modern Physics 54, 687 (1982)
168B Spectroscopy in a New Light, Science 217, 9 (1982)

168C Fortechritte in der Laserspektroskopie, Naturwissenschaftliche
Rundschau, 36, 247 (1983).

168D Spectroscopy in a New Light, Uspekhi Fizicheskii Nauk (USSR)
138, 205 (1982) .

168E. Spectroscopy in a New Light, Postepy Fizyki (Poland)
Tom 34, Zeszyt 4 (1983) .

168F. Spectroscopy in a New Light, Czechoslovak Journal of Physics,
Section A, Volume 33 (1983) .

313

169. Ultraviolet Sum-Frequency Generation Utilizing Optical Pair

Interactions in Solids (S.C.Rand, L.-S.Lee and ALS),
Opt. Comm. 42, 179 (1982).

170. Spectroscopy: Present and Prospects, in New Techniques of Optical

and Infrared Spectroscopy, The Royal Society,
London (1982), p. 219.

170A. Spectroscopy: Present and Prospects, Phil. Trans. Roy. Soc. London,
Series A, 307, 685 (1982).

171. Lasers and Physics: A Pretty Good Hint, Physics Today 35, 46 (1982).

172. Concluding Remarks, in Atomic Physics 8, I.Lindgren, A.Rosen,

and S.Svanberg, eds, Plenum Press, New York (1983), p. 565.

173. A Scanning Pulsed Polarization Spectrometer Applied to Na 2 ,

(A.J.Taylor, K.M.Jones, and ALS) , J. Opt. Soc. Am. 73, 994 (1983)

174. Lasers and Their Uses (Charles H. Davis Lecture Series, Fall 1983),

sponsored by Naval Studies Board, National Research Council,
Academy Press, Washington (1983).

175. Advances in Laser Spectroscopy, Interdisciplinary Science Reviews,

Volume 9, Number 1, 59 (1984).

176. Lasers in Historical Perspective, IEEE J. Quant. Electr.,

Centennial Issue (1984).

177. Cascade Stimulated Emission in the Sodium Dimer (Z-G. Wang, Y-C.Wang,

G.P.Morgan, and ALS) , Opt. Comm. 48, 398 (1984).

178. Cooperative Energy Transfer Among Pr 3+ Ions in LaF 3 (L.-S.Lee,

S.C.Rand, and ALS, Phys . Rev. B 29, 6901 1984).

179. Generation of Coherent UV Radiation by Optical Wave-Mixing Processes

in Atomic Potassium, (P. -L.Zhang, Y. -C.Wang, and ALS),
J. Opt. Soc. Am. Bl, 9 (1984).

180. Laser Spectroscopy, Past, Present, and Perhaps Future, in

Proceedings of the International Conference on Lasers "82,
STS Press, McLean, Virginia (1983), p. 1.

181. Three-Photon-Excited Fluorescence Detection of Atomic Hydrogen

in an Atmospheric-Pressure Flame (M.Alden, ALS, S.Svanberg,
W.Wendt, and P. -L.Zhang), Optics Letters 9, 211 (1984).

182. Two-Photon Resonant Optical Processes in Atomic Potassium

(P. -L.Zhang and ALS), Canadian J. of Physics, 62, 1187 (1984)

183. Laser Emission from Double-Minimum State (2) 1 + u to(2) 1 Z% by

Optical Pumping in Sodium Dimer (Z. -G.Wang, H.-R.Xia, L.-S.Ma,
Y. -Q.Lin, I. -S.Cheng, and ALS) in Proceedings of the
International Conference on Lasers, LASERS '84, STS Press,
McLean, Virginia (1985) .

314

184. Comment of the Asymmetry Observed in Intracavity Absorption Line

Profiles (W.T.Hill III, T.W.Hansch, andALS), accepted,
Applied Optics, September, 1985.

185. Lasers and Mankind, Franklin Lectures in Science and Humanities,

Auburn University, Alabama, May 6, 1985.

186. Laser Spectroscopy Using Beam Overlap Modulation (T.P.Duffey,

D.Kammen, ALS, S.Svanberg, H.-R.Xia, G. -G.Xiao, and G.-Y.Yan),
Optics Letters, 10, 597 (1985).

187. 25 Years of Lasers, Encyclopedia Britannica Yearbook of Science and

the Future, 1985.

188. High-Contrast Doppler-Free Transmission Spectroscopy, (S.Svanberg,

G.-Y.Yan, T.P.Duffey, andALS), Optics Letters, 11, 138 (1985).

189. Two-Photon Resonances in a Sodium-Potassium Mixed Alkali Vapor

(G.P.Morgan and ALS), J. Opt. Soc. Am. B, 1033 (1986).

190. Saturation Spectroscopy for Optically Thick atomic Samples,

(S. Svanberg, G.-Y.Yan, T.P. Duffey, W.-M. Du, T.W. Hansch and
ALS), J. Opt. Soc. Am. B, 462 (1987).

191. Principles of Lasers, in Proceedings of Impacts of Physics on the

Frontiers of Medicine I. Lasers, Lake Buena Vista, Florida, Dec.
8-10, 1986

192. Constants of the Ss 1 ^, State of Na 2 , From Two-Photon Spectroscopy,

(G.-Y. Yan, T.P. Duffey, W.-M. Du, andALS), J. Opt. Soc. Am.
B4, 1829 (1987)

193. Intracavity Absorption Detection of Magnetic-dipole Transitions in

18 O 2 , and the determination of the b^*, (v=2) State Rotational
Constants, (W.T. Hill III and ALS), J. Opt. Soc. Am. B5, 745
(1988)

194. Atoms, Molecules and Light, in Modern Physics in America: A

Michelson-Morley Centennial symposium, William Fickinger and
Kenneth Kowalski, eds . , American Institute of Physics AIP
Conference Proceedings 169, American Institute of Physics, New
York (1988), p. 26

195. The Potential of the (S) 1 ^, State of Na 2 , by Two-Step Excitation

Spectroscopy, (G.-Y. Yan, B.W. Sterling, and ALS), J. Opt. Soc.
Am. B5, 2305 (1988)

196. Doppler-free UV Excitation Spectra of C^-X'E*,, in Na 2 , by

Modulated Population Spectroscopy, (G.-Y. Yan, B.W. Sterling,
T. Kalka and ALS), J. Opt. Soc. Am. B6, 1975 (1989)

197. Experimental Observation of the (3) 1 L U * State of Na 2 , by

Deperturbation of the C 1 u -X 1 2' t g System, (G.-Y. Yan and ALS),
J. Opt. Soc. Am. B6, 2309 (1989)

315

198. First Observation of Perturbations on the C 1 ,, State of Na 2 , by CW

UV Modulated Population Spectroscopy, (G.-Y. Yan, B.W. Sterling
and ALS), Laser Spectroscopy IX, Proceedings of the Ninth
International Conference on Laser Spectroscopy, M.S. Feld, J.E.
Thomas, and A. Mooradian, eds . , Academic Press, New York,
pp 402-404 (1989)

199. Relaxation Oscillator Detection of Optogalvanic Spectra, (G.-Y.

Yan, K.-I Fujii, and ALS) , Optics Letters 15, 142 (1990)

200. A New Method for Detecting Optogalvanic Effect and Plasma

Oscillation, (G.Y. Yan, K.-I. Fujii, and ALS), Proceedings
of the Fourth International Conference on Laser Aided Plasma
Diagnostics, Fukuoka, Japan, pp 415-420 (1989)

201. Discovering Science (ALS) in A Voyage of Discovery: Messages from

Nobel Laureates, Israel Halperin, editor

201a. Discovering Science (ALS) in book for third world scientists, O.K.
Nachtigall, editor

202. Sharp Optical Lines in Rare Earth Barium Copper Oxides (D.W.

Shortt, M.L. Jones and ALS) , Phys . Rev. B42,132 (1990)

203. Felix Bloch (ALS) in Yearbook of American Philosophical Society

1989, 174 (1990)

204. Detection of Sharp Absorption Lines in Very Thin Nd 3 Films, (D.W.

Shortt, M.L. Jones, A.L. Schawlow, R.M. Macfarlane and R.F.C.
Farrow), J. Opt. Soc. Am. B8, 923 (1991)

205. The Beginnings of Lasers, in Proceedings of Tropical Laser 90,

International Laser Therapy Association, T. Ohshiro, Ed. (1990)

206. Optical Line Spectra in Metallic (Nd, Ce) 2 ,Cu0 4 . x , (M.L. Jones, D.W.

Shortt, B.W. Sterling, ALS and R.M. Macfarlane), submitted to
Physical Review B (1991)

207. Measurement of Diode Laser Characteristics Affecting Its Tunability

with an External Grating, G.-Y. Yan and A.L. Schawlow,
J. Opt. Soc. Am. B9, 2122 (1992)

208. Laser, Licht und Materie, Naturwissenschaftliche Rundschau

45, 211 (1992)

209. Ultrasensitive Absorption Spectroscopy of Lanthanide Solids, (M.L.

Jones, D.W. Shortt, B.W. Sterling and A.L.S.), submitted for
Festschrift for Stanley S. Hanna (1992)

210. Laser Technology for the Next Century, A.L. Schawlow in Proceedings of

Laser Advanced Materials Processing, Nagaoka, Japan, June 8-12, 1992
A. Matsuoka, editor

211. Perspectives On Laser Spectroscopy, in Proceedings of Enrico Fermi

Summer School, Varenna, Italy, June 29-July 10, 1992, Frontiers
in Laser Spectroscopy, T.W. Hansch and M. Ingiusco, editors, North
Holland (1994) page 1.

316

212. Absorption Spectroscopic Measurement of Atomic Density in

Laser-Induced Vapor Plume, T.P. Duffey, T.J. McNeela, J. Mazumder,
and A.L.S., Appl . Phys . Lett. 63, 2339 (1993)

213. Spectral Lineshapes for First-Surface Reflection from Solids, B.W.

Sterling, A.L.S., and M. Jones, submitted to J.O.S.A. B, 1994

214. Lasers in Perspective, A.L. Schawlow in Proceedings of the

6th International Symposium on Advanced Nuclear Energy Research,
Mito, Japan (Japan Atomic Energy Research Institute, 1995), page 3

215. Fifty Years of Physics and Physicists, A.L. Schawlow, Physics in

Canada, 1995

216. Absorption spectroscopic measurements of plume density and temperature

in production of nanocrystalline NbAl 3 by laser ablation
deposition, T.P. Duffey, T.G. McNeela, T. Yamamoto, J. Mazumder and
A.L. Schawlow, Phys. Rev. B, 14652 (1995)

316a

APPENDIX B

ART SCHAWLOW AND

f""^

NEW ORLEANS

PLAYED IT TORONTO'S FIIEST AMATEII
JAZZ MUSICIANS FEATDRIRI THE

"QUEEN CITY JAZZ BAND"

AMD OTHERS

PLAYTER'S HALL "/.KM MAY 5TH 8.30

Paster autographed by the musicians, Hay 5, 194B

316b

Delta Jazz Band, Lansdoune Assembly Hall, December 2, 194B

Ron Sullivan, Johnny Mitchell, F.L. Priestly, Bob Donnelly
Art Schaujlotu, Jim Johnson, Barry Habberman, Ken Glandfield

316c

PERSONNEL:

PROGRAM:

DELTA JAZZ BAND

"The Jazz Band Ball"

Lansdotune Assembly Hall

Thursday, December 2, 194B

B:45 - 9:15 pm

Bob Donnelly

Ron Sullivan

Johnny nitchell

Art Schaulouj

Barrg Habberman

F. L. Priestly

Ken Glandfield

Jim Johnson

Trumpet

Trombone

Clarinet

Piano

Banjo

Bass

Drums

You've Gotta See Plama Ev'ry Night C vocal Donnelly 5

Ja-Da

Tin Roof Blues

Darktouin Strutters' Ball

Slow Blues

Just A Closer Walk With Thee

PERSONNEL:

PROGRAH:

C13
C1D
C1D

C1D

QUEEN CITY JAZZ BAND

"The Jazz Band Ball"

Lansdoiune Assembly Hall

Thursday, December 2, 1348

9:15 - 10:15 pm

Frank tloujat

Bud Hill

Johnny Philips

Clyde Clark

Lyle Glover

Harvey Hurlbut

Jack Beattie

Trumpet

Trombone

Clarinet

Piano

Banjo

Bass

Drums

Red Light Rag CthemeJ

Cut It Loose CMy Bucket's Got A Hole In It)

Working flan Blues

I Thought I Heard Buddy Bolden Say

Dallas Blues

Squeeze He

Ballin' The Jack

Muskrat Ramble

Tin Roof Blues

Canal Street Blues

Nobody Knows You When You're Down And Out

Red Light Rag CthemeD

FOOTNOTE:

C1D This tune was recorded, and sold as a ten-inch acetate record by Warner
8 Herrifield Recording Service, Toronto.

316d

2. Live Appear? nces

My first introduction to the Jazz fraternity in Toronto came on
Thursday, tlarch 6, 1947, when the Jazz Society of Toronto held a concert of
recorded Jazz, and invited the general public. They presented a
well-balanced program of twenty-eight records covering the dixieland, New
Orleans, blues, Chicago, and revival schools of Jazz. Although I had been
collecting records for five years, the variety of styles came as a revelation
to me. I can still remember sitting on those wood chairs before the meeting
began, reading the handbill, and wondering what NQRK and QDJB meant!

The Queen City Jazz Band, led by pianist Clyde Clark, was ths first
amateur jazz band I ran across in Toronto. It had been playing for several
years. In fact, at three private recording sessions in 1346, 1347, and 1348,
they had recorded twelve sides which were issued as custom-made acetate
records C2) .

Ply first meeting with the band occurred at .a dance presented by Art
Schatulow and the Jazz Society of Toronto on Hay 5, 1348. It was, for me,
merely the first of many dances in various halls around Toronto, including
Centre Island (a resort area offshore in Toronto harbour).

ft memory comes back to me of one of these sessions - a warm summer
evening, a refreshing breeze blowing in from the lake, an open-air dance
floor called The Lido Deck on the main street of Centre Island, and up on tha
bandstand the Queen City Jazz Band with all seven men playing their hearts
out .

I didn't dance at these sessions - I Just listened, spellbound, and
wrote down the names of the musicians and the tune titles. When I returned
home, I typed up the lists and filed them away. I did this for all the
sessions described in this paper. So there's no faulty memory here; you can
rely on the accuracy .

The first time the band was recorded at a dance mas on July 21, 1348,
when Art Schawlouj and Ulilf Goldstick set up a tape recorder and tried to
record most of the music. ftfter the dance we all drove over to Uilf 's place
to hear the results. ftlas, the tapes were unusable. It's a pity; I remember
that the closing number, Canal Street Blues, was a long version, with time
for a solo by each member of the band and each guest who was sitting in.
Note that Bud Hill played string bass that night. When I expressed my
surprise to Bud, he said, "Heck, any trombone player can play bass."

In September of 1348 Ken Dean left the Queen City Jazz Band and formed
his own band, Ken Dean's Hot Seven. Now there were two amateur bands to
follow! For a teen-ager like me with a deepening appreciation of Jazz, that
wasn't at all hard to take. The dance at the Todmorden Memorial Hall on
August 13, 1948, was the first appearance of the band.

In October, Bob Brimson played a dance at Coliton's fluto Livery with a
sextet that I presume he put together for the occasion. He used four neiu
members of the Queen City Jazz Band, plus Bud Hill's brother Ed on clarinet.
The band played stock arrangements, interspersed with hot Jazz tunes. The
singer, Jean Nesbitt, was Bob Brimson's girl friend. When she sang her
dreamy vocals, two young bucks from the audience stood in front of her and
swayed from side to side. Bob was ready to punch them out, but Jean felt
they were sincere, and was flattered. I was sitting on the floor beside Bud
Hill at one point and the arrangement must have been boring, because Bud
leaned over to me and offered to let me blow his trombone part. I told him I
hadn't a clue how to play trombone, but I don't think Bud would have minded.

317 APPENDIX C

IMPACT OF
BASIC RESEARCH
ON TECHNOLOGY

Edited by

Behram Kursunoglu

and
Arnold Perlmutter

Center for Theoretical Studies

University of Miami

Coral Gables, Florida

PLENUM PRESS NEW YORK-LONDON 1973

318

FROM MASER TO LASER

Arthur L. Schavlow

Department of Physics

Stanford University, Stanford, California

In some vays , lasers seem to "be the realization
of one of mankind's oldest dreams of technological pover
Starting with the "burning glass, which was known to the
ancient Greeks, it was natural to imagine an all-
destroying ray of overpower ingly intense light. Francis
Bacon, in his l62T New Atlantis , imagined that the in
habitants of this Utopia had "all multiplication of
light, which we carry to great distance, and make so
sharp, as to discern small points and lines." In War of
the Worlds. H.G. Wells' 1898 novel, Martians nearly
conquered the earth with a sword of light. In 1923, the
Russian novelist Alexei Tolstoi wrote The Hyperboloid of
Engineer Garin. Then, in the 1930's the Buck Rogers
comic strip often made use of a disintegrator gun.

Yet many old dreams, which have more or less come
true in this century, are realized only more or less.
Men dreamed of flying like birds and now they do fly,
but it is not at all like birds. Similarly, most lasers
deliver far less than the destructive death rays of
science fiction but their light has properties, such as
monochromaticity and coherence, which go far beyond the
old dreams .

Rays of any kind were far from the minds of Charles
H. Townes and myself when, in 1957, we began to think
seriously about the possibility of optical masers .
Rather, we were thinking of what was already a classic
problem in pure technology: to find something which

319

SCHAWLOW

vould act like a radio tube and generate shorter radio
waves. "Daedalus" has pointed out in New Scientist
(December 22, 1965) that there is a body of research
vhich seeks to find ways to do things for their own
sake. There may well be no immediate application in
sight, but such pure technology "like pure science,
often has to masquerade as the applied variety in order
to get funds." Some problems in pure technology may
appear as frivolous as "the development of a square
gramophone record played with such a perfect quadri
lateral-linear motion that corner effects are imper
ceptible." But others play a serious part in the
development of technology. Even though their appli
cations are not immediately foreseeable, they do parallel
or extend lines of enquiry which have been fruitful in
the past .

Throughout the twentieth century, scientists and
engineers have sought to extend radio techniques to
shorter wavelengths. As a boy in the 1930's I had read
in the Radio Amateur's Handbook that after World War I,
the amateurs "couldn't go up [in wavelength], but we
could go down. What about those wavelengths below 200
meters? The engineering world said they were worthless
--but then, they'd said that about 200 meters, too."
After preliminary tests and "some months of careful
preparation, two way amateur communication across the
Atlantic finally became an actuality when Schnell, 1MO,
and Reinarty, IXAM , worked for several hours with 8AB,
Deloy in France, all three stations using a wavelength
of about 110 meters." Still shorter waves, with lengths
ranging from 10 to 80 meters, were found to make possible
world-wide communications.

In the 1930's, amateurs and others found ways to
use very high frequency waves whose lengths were shorter
than about ten meters. These waves did not travel
much more than line-of-sight-distances , but they were
found to be suitable for reliable, broad-band broad
casting such as for television or stereo music. With
inventions like klystrons and cavity magnetrons it be
came possible to explore the properties of waves of
centimeter lengths. These waves were not suitable for
"broadcasting since they could be stopped by almost any
obstacle. However, their short wavelength made them
useful for high-definition radar and for relaying broad
band communications.

From all this, it seemed overwhelmingly probable

320

FROM MASER TO LASER 115

if some way could be found to generate shorter wave
lengths, there would be uses for them. Some of the
uses would be obvious, like communications, but there
was a good chance that the unforeseen uses would be even
more exciting. There were, of course, ways of producing
shorter electromagnetic waves from many kinds of hot
bodies. Such sources, like the sun and electric lamps,
could be quite bright, but they lacked several of the
desirable properties of electronic oscillators. The
output was always a rather broad band of frequencies.
Since the excited atoms or molecules radiated spontane
ously and independently of each other, their output did
not have spatial coherence. Moreover in the infrared,
and especially for the longer infrared wavelengths,
spontaneous emission was relatively slow so that the
power emitted was small.

One of the requirements for building an electronic
oscillator to generate such short electromagnetic waves
is the resonators to tune it. For microwaves, which
have lengths ranging from millimeters to centimeters,
tuning is usually achieved with some kind of cavity
resonator whose dimensions are comparable to the wave
length. When the desired wavelengths are a small
fraction of a millimeter, construction of cavity reso
nators becomes a very difficult task. But nature has
provided us with many kinds of atoms and molecules with
natural resonances throughout the infrared and optical
wavelength regions. Even when I was an undergraduate
student, in the late 1930's, it seemed to me- that there
ought to be some way to use these in amplifiers or
generators of infrared waves. But I did not know
enough quantum physics to even begin trying to find a
way to do it. Very likely others had similar vague
ideas and, indeed, the formal similarity between atomic
absorptions and resonances of tuned circuits had long
been recognized.

The connection between radio waves and atoms was
again emphasized by the growth of radiof requency and
microwave spectroscopy in the years after World War II.
I was then a graduate student at the University of
Toronto, having interrupted my studies for war work
teaching at the University and then microwave antenna
engineering in a radar factory. At the University of
Toronto, we did not have the facilities for the
glamorous fields like nuclear physics and radiof requency
resonances. So, I was happy to work, under Professor
Malcolm F. Crawford, on hyperfine structure in the

321

116 SCHAWLOW

spectra of atoms. With another graduate student,
Frederick M. Kelly, I constructed an atomic "beam light
source to give spectral lines sharp enough so that
their hyperfine structure could "be analyzed. Another
graduate student, William M. Gray, constructed a spectro-
graph and a Fabry-Perot interferometer to use with our
source. Thus I became highly familiar with this inter
ferometer, consisting of two parallel, partially-
transmitting mirrors facing each other. This instrument
had been studied in undergraduate optics classes, but
even though most of the work with the interferometer
was done by the others in our group, I did learn more
about it during our research. When I began to think of
resonators for light waves a decade later it seemed
natural to start with the Fabry-Perot structure of two
mirrors facing each other.

In the postwar years, it seemed to me that the
most exciting physics research was at Columbia University
I.I. Rabi was still active, and W. Lamb and P. Kusch had
recently made discoveries which were immediately re
cognized as important and later brought them Nobel
Prizes. I wrote to Rabi, and he suggested that I apply
for a postdoctoral fellowship to work with Associate
Professor C.H. Townes. This fellowship was provided by
the Carbide and Carbon Chemicals Corporation, a division
of Union Carbide, to support research on the application:
of microwave spectroscopy to organic chemistry. I had
neither knowledge of nor interest in organic chemistry,
but microwave spectroscopy was an attractive new field.
I must also confess that I had not heard of Charles
Townes, although I soon found that he had recently
published a number of discoveries. At any rate, I
applied for and was awarded the fellowship.

After coming to Columbia University, I learned that
although microwave spectroscopy can be use-d to determine
the structure of organic molecules and for analysis,
that was not the only reason for Carbide and Carbon
Chemicals' sponsorship. As early as August, 19^5, Dr.
H.W. Schulz, a member of their research staff, had
written a memorandum to propose a new type of catalysis
"to employ electromagnetic radiation of a specific fre
quency to effect activation of reacting molecules by
induced resonance." In this memorandum he stated that
"The pertinent frequency range would cover the long and
short wave radio bands as well as the infrared, visible
and ultra-violet spectra. A literature search indicates
that this principle has previously been employed only in

322

FROM MASER TO LASER 117

the case of photocatalysis . " As his study proceeded,
Dr. Schulz came to realize that resonance catalysis
would need the tunability and power of radio generators,
"but at a shorter wavelength than was available from
existing oscillators. After various alternatives were
considered, it was decided to support long range research
aimed in this general direction at a major university.

At Columbia University, there was a Radiation
Laboratory group in the physics department, continuing
a program from the wartime days on magnetrons to
generate millimeter length radio waves. Also there was
Townes, who had recently come from Bell Telephone
Laboratories and was making pioneering studies of the
interaction between microwaves and molecules. The
laboratory was supported by a Joint Services contract
from the U.S. Army, Navy and Air Force, with the general
aim of exploring the microwave region of the spectrum
and extending it to shorter wavelengths. Dr. Harold
Zahl of the Army Signal Corps and Paul S. Johnson of the
Air Force Office of Scientific Research were among those
active in the sponsorship of this program. Captain
Johnson also organized a millimeter wave study committee
and asked Townes to be its chairman. As Townes has
recounted, it was on the morning of a meeting of this
committee that he conceived the idea of the maser.

Thus during my stay at Columbia there was wide
spread recognition that it was interesting to find
better ways to generate wavelengths shorter than those
produced by existing electronic devices. But nobody
had a good idea of how to do it, and so Townes 1 group
concentrated on exploring the structures of molecules
and their interaction with microwave radiation. This
turned out to be the right decision, for a detailed
understanding of the ammonia molecules was Just what
Townes needed to invent the maser in the Spring of 1951.
In this ammonia maser, a beam of ammonia molecules
would pass through a suitable electric field which would
accept those in excited states and reject the unexcited,
absorbing molecules. The excited molecules could be
stimulated to emit microwave radiation inside a cavity
resonator, a metal box having dimensions comparable
with the wavelength.

Townes told me about his idea in May or June of
1951, and it seemed promising. I would have liked to
work on it, but my time at Columbia University was coming
to an end and I had accepted a Job in solid state physics

323

118 SCHAWLOW

at Bell Telephone Laboratories.

My vork took me quite far away from problems of
generating electromagnetic radiation. I kept in touch
with Townes, "because we were writing a book on Micro
wave Spectroscopy and I spent nearly every Saturday at
Columbia University. Thus I heard from time to time
about the problems and progress of the work on the
maser and was delighted when it first operated in 195^.
At about that time, interest in masers began to pick up
at Bell Telephone Laboratories and two years later, G.
Feher, H.E.D. Scovil and H. Seidel built the first
three-level solid state microwave maser following a
proposal by Nicolaas Bloembergen of Harvard University.
While the original ammonia maser had been primarily
useful as a frequency standard or as a sensitive
detector for studies of the ammonia molecules, the
solid state maser was something that could actually be
used for communications and radar. It had a broader
band width and could be tuned by changing the strength
of a magnetic field. Not long afterwards, C. Kikuchi
of the University of Michigan showed that ruby was a
good material for such masers. Joseph Geusic, who came
to Bell Labs from Ohio State University about that time,
where he had done his thesis with J.G. Daunt and had
for the first time measured the mivrowave resonances in
ruby, was one of those who became active in designing
and perfecting ruby masers.

I did not participate in any of this except as a
spectator, being busy with research on superconductivity
and, for a time, nuclear quadrupole resonance. I also
taught twice a three month course in solid state physics
for the engineers in the program which Bell Laboratories
had established for new engineers coming from college
with Bachelor's or Master's degrees.

When parametric amplifiers were rediscovered by
Harry Suhl, we thought perhaps this might somehow be a
clue to producing shorter wavelengths and I spent a
little time learning about them. I even built an audio
frequency parametric amplifier too. It may well have
been the first one at Bell Labs since the work of
Peterson some years earlier, which had by then been
nearly forgotten and was not known to me.

By 1957, I was coming to think that the time was
right for a serious investigation as to whether one
could build some kind of an infrared maser. Naturally,

324

FROM MASER TO LASER 119

I was thinking primarily about the wavelength region
just a little shorter than could be obtained by radio
tubes. Townes had hoped initially that his ammonia
maser would oscillate at a wavelength of a half milli
meter, but in the final device the output was at one
and a quarter centimeters wavelength, which is well
within the region spanned by existing microwave tubes.
I remember attending a conference on low temperature
physics at the University of Wisconsin in August 1957
and chatting there with Michael Tinkham, who was then
at the University of California and had been doing some
far-infrared spectres copy . This kind of spectroscopy
was very difficult, because the existing light sources
were extremely weak and so I suggested that it really
ought to be possible to build some kind of a maser to
produce a stronger source. Tinkham mentioned that iron
in crystals had energy levels in a right wavelength
region, but neither of us did anything more about it at
that time .

A few weeks later, about October of 1957, Charles
Townes visited Bell Labs and we had lunch. Townes had
been consulting with the Laboratories for about a year,
but his contacts were with the maser people and I had
not had any serious discussions with him. He told me
then that he was interested in trying to see whether an
infrared or optical maser could be constructed, and he
thought it might be possible to Jump over the far infra
red region and go to the near infrared or perhaps even
visible portion of the spectrum. He had made some notes
and said that he would give me a copy. We agreed that
it might be worthwhile for us to collaborate on this
study and so we began.

We both realized that the three-level and four-
level pumping schemes, used in microwave masers, could
be used with incoherent light as a pump if we could get
enough power from the incoherent light. Indeed, Townes
had envisioned optical pumping of masers as early as
195^, and had mentioned the method in his basic maser
patent. Just as in the microwave maser the ammonia
molecules are excited independently and enter the
resonator quite individually, so we could excite in
dividual atoms or molecules in any kind of a maser at
random. The synchronization would be achieved by a
wave stored in a resonator.

However, excited atoms lose their stored energy
even if they are not stimulated. In solids at

325

120 SCHAWLOW

radiofrequencies the energy is lost "by transfer to the
crystal vibrations where it "becomes heat, "but in the
visible region spontaneous radiation may be more impor
tant. It was not at all obvious whether one could get
enough excited atoms despite spontaneous emission, and
the only way to answer this question seemed to be to
study the properties of some fairly simple substances
which might be calculable. Although solids and liquids
are known to emit strongly, gases are simpler and better
understood and the simplest gases are those consisting
of individual atoms. Townes thought he saw a suitable
system in thallium vapor and had described it in the
notes he gave me.

The thallium atoms would be excited from the
ground state (6p) to a higher one (either 6d or 8s) by
ultraviolet light from a thallium lamp. Such lamps
were in use in Kusch's laboratory at Columbia University
for experiments on optical excitation of thallium atoms
in an atomic beam resonance experiment. Townes had dis
cussed with Gordon Gould, a student of Kusch's who was
working on the atomic beam experiment, the properties
of thallium lamps to find out how much power could be
expected from them. Atoms excited to the 6d or 8s
level would, according to Townes 1 scheme, rapidly
radiate part of their stored energy and drop to the Tp
level which would be the upper level for maser action.
From there they could be stimulated to make transitions
to a 7s level which would normally be empty.

After looking at this, I saw a flaw in it, in that
the rate of spontaneous transition was greater out of
the 7s to the 6p than from the 6d or 8s into the 7p"
This means that the 7p state, which was to hold atoms
to be stimulated, would empty faster than it filled.
Laser action might not be impossible under those circum
stances, but it would be difficult, and it pointed out
a general problem with this sort of a cascade operation
in atoms. It is rather usual, although there are ex
ceptions, that the various excited states have progres
sively longer lifetimes as you go up except for the
ground state whose lifetime is essentially infinite.

However, if Townes' thallium scheme was not
immediately workable it did make an important point.
It would be easier to do a theoretical analysis for
transitions of a maser to emit radiation in or near the
visible than it would be for the submillimet er region,
where so little was known experimentally. It might ever

326

FROM MASER TO LASER 121

be that it would "be actually easier to "build one in the
near-visible region because the spacings between energy
levels in that region are large enough so that thermal
excitations do not quench excited atoms as quickly as
they do for levels with the smaller spacings corre
sponding to the far infrared. So, we searched for suit
able energy levels and transitions in some atoms which
might be excited to emit radiation in this portion of
the spectr um .

In this quest, we had a good deal of information to
guide us, although not all the questions we wanted had
been asked. The energy levels of many atoms were tabu
lated in the volumes prepared by Charlotte Moore of the
National Bureau of Standards. Some transition proba
bilities were given in the Landolt-BBrnst ein Tables, in
a Table edited by L. Biermann. These would give us a
start and would give references to more complete in
formation in original papers.

How many excited atoms would we need? Townes had
the maser equation which he modified by letting sponta
neous emission loss replace the other kinds of losses
which had been dominant for microwave masers. The equa
tions are given in the paper which we published in 1958,
but essentially what he did was to imagine light waves
traveling in a box which could be thought of, for the
derivation, as a rectangular box with reflecting walls.
Light would be lost only at the walls, and, knowing that
light waves travel at the velocity of light, one could
easily calculate the average time between wall reflec
tions. Then from that you could get the ratio of energy
lost to energy stored for an electromagnetic wave in the
box, provided you know the reflection loss each time the
wave reaches a wall. The rate of stimulated emission of
energy from the excited atoms depends on the intensity
of the stored wave, as do the losses. One needs then to
calculate how many excited atoms are needed to overcome
the losses. Now the excited atoms will radiate in a
short time which might range anywhere from billionths of
a second to perhaps thousands of a second and must be
replaced on the average once each lifetime. Thus we can
calculate the number of excited atoms neoded per second
to just make up the losses in this resonator. If we had
more than that we can increase the losses by' opening the
hole or making the walls partly reflecting so that we
can take out some of the energy generated.

In the microwave regions, the strength of the

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122 SCHAWLOW

interaction of the molecules with the stored electro
magnetic wave is visually measured "by the dipole moment
of the molecule. One can give an effective dipole
moment for an optically excited atom, but it is more
usual to use the quantity known as the oscillator
strength, f, which is related to the dipole moment.
This is the quantity most commonly tabulated in places
such as the Landolt-Bo'rnstein Tables and more extensive
compilations which have appeared since then. The
oscillator strength, f, indicates the effective number
of electrons available for the particular atomic res
onances and may range from one down to a very small
fraction of one, or in a few exceptional cases it can be
greater than one but not commonly. It can be measured,
for example, if you know how many atoms there are in the
ground state by determining the strength of the ab
sorption of light within the band which the atom can
absorb. Measurement for excited state is more diffi
cult because it is not easy to know just how many atoms
there are in each of the excited states but some measure
ments have been made.

Probability of stimulation by a given wave is
proportional to oscillator strength, and so also is the
gain for a given number of excited atoms. Thus to get
a large gain without exciting very many atoms, we would
wish to have a large oscillator strength. However, since
the oscillator strength measures the interaction be
tween the atom and an electromagnetic wave, the rate of
spontaneous emission is also proportional to the oscil
lator strength. That is, the greater the oscillator
strength the shorter the lifetime of the excited state
and the faster we have to replace the excited atoms. It
turned out, then, that it did not really matter what
the oscillator strength was for the particular transi
tion. If it was high, we would need only a few atoms
but we would have to replace them frequently. If it
was low, we would need many atoms, but would not have
to replace them as often. Thus the oscillator strength
would not matter at all, if atoms lost their excitation
only by emitting the desired radiation. But if there
are competing processes, it is helpful if the desired
one has a large oscillator strength.

Another factor, important for the gain of a
particular atomic resonance, is the width of the spec
tral line. The probability of stimulated emission,
and hence the gain from a given number of excited atoms
is inversely proportional to the width of the spectral

328

FROM MASER TO LASER 123

line. Fortunately, for a gas at low pressure, the
linewidth is known to "be given "by the Doppler effect
from the thermal motions of the atoms. This is easily
calculable. In solids and liquids the linewidths are
much more variable. When, later, we "began to think
seriously about these materials, we had to make our own
measurements of linewidths.

We concentrated our study on the simplest atoms,
the alkali metals. While the hydrogen atom's spectrum
is perhaps even simpler and more theoretically calcul
able, hydrogen exists in the form of molecules which
have to be disassociated and the efficiency of the
dissociation would introduce additional uncertainty. The
alkalis have only one electron outside a closed shell
and so can be thought of as nearly one-electron atoms.
Their energy levels are well known and the metals are
not hard to vaporize. Moreover, alkali vapor lamps are
commercially available by a number of companies and in
deed sodium vapor has been widely used for street light
ing. I chose to look most carefully at potassium for a
rather trivial reason. Both the first and second members
of the principal series of potassium vapor lie in the
visible region. That is, one could pump potassium atoms
from the ground Us state up to the 6p with visible
UoUTA light from a potassium vapor lamp and then monitor
the progress of these atoms back to the ground state by
looking at the red line emitted when atoms drop from the
5p to the Us state. In the other alkalis, one or the
other of these transitions lies in the infrared or
ultraviolet. These are obviously not very important
considerations, but I had essentially no optical
equipment at all at the time and was thinking whether
one could begin experiments easily and cheaply. More
over, it did seem that any conclusions from one atom
would be pretty much applicable to the others.

I bought some commercial Osram alkali vapor lamps
and one of my colleagues, Robert J. Collins, measured
the power output of some of these lamps for me. Collins
had done his thesis research in spectroscopy and was by
that time a Bell Laboratories physicist working on some
infrared spect ros copic studies. He found that each of
the lamps generated to 0.08 milliwatts in the kOhlR line.
Of course this was only one small lamp and was not
designed for maximum power. One could imagine buying
large arrays of such lamps or, if necessary, building
them. But the 0.08 milliwatts, if we could use all of
it, would be sufficient to excite quite a large number

329

12U SCHAWLOW

of atoms in a potassium vapor cell. So as our calcu
lations progressed, vith the aid of tables of measured
oscillator strengths published years "before, it "began to
look that you could indeed get enough excited atoms to
obtain measurable amplification in the excited state.

During this time ve had not been paying too much
attention to the resonator vhich we would need to
complete the maser oscillator. I had in mind from the
beginning something like the Fabry-Perot interferometer
I had used in my thesis studies. I realized, without
ever having looked very carefully at the theory of this
interferometer, that it was a sort of resonator in that
it would transmit some wavelengths and reject others.
Such an interferometer might typically have had mirrors
with diameters of perhaps 7 cm and spacing of perhaps
that much or less. Somehow it must have been implicit
in our thinking that the absence of the side walls did
not really matter too much. However, as we began to
feel satisfied that it was possible to get sufficient
excitation our attention turned more toward the properties
of the resonator. The number of modes of oscillation
of such a resonator, having dimensions tens of thousands
of times larger than the wavelength, was enormous even
in the limited range of frequencies which the atoms
could amplify.

All physicists learn how to calculate the number of
modes of waves in a large volume somewhere around the
end of undergraduate or the beginning of graduate studies.
This kind of calculation is important, for example, for
estimating the spontaneous emission lifetime of excited
atoms and for the derivation of the well known law for
the intensity for emission from a heated black body.
The same kind of counting up of modes is used in the
Debye theory of specific heat, where the thermal motions
of the atoms in a solid are considered to be entirely
equivalent to a superposition of all possible random
thermal waves of wavelengths from very long ones to those
whose wavelength is Just twice the spacing between the
atoms. I have been through this as an undergraduate,
but my memory had been particularly refreshed when I
taught the Debye theory of specific heat to the en
gineers at Bell Telephone Laboratories. However, at
first I simply looked at the number of modes and then
began to think what the output of the optical maser
might be like if we had one.

Martin Peter, another colleague at Bell Laboratories,

330

FROM MASER TO LASER 125

vas particularly insistent that ve should find some way
to reduce this enormous number of possible modes. Other-
vise, he felt the optical maser, if it did oscillate,
vould jump rapidly from one mode to the other and not
produce any very recognizable kind of oscillations.
The coherence of the radiation vould be continually
interrupted by jumps from one mode to a different one.
Tovnes had recognized the importance of this multimode
problem, and it had kept him for a long time from
proceeding vith short-vave masers. When ve began our
vork together, he believed both that it vas important
to damp out other modes and assure that there vas good
mode control, but that even though he could see no
system vhich vould do this completely, one should go
ahead in any case, thinning out the modes as much as
ideas vould permit. He expected that the oscillator
vould oscillate momentarily on a single or a limited set
of modes because of nonlinear it ies , but that it vould
also jump fairly rapidly betveen different modes. He
believed that one could easily determine that the system
had gone unstable and vas vorking, and that the propertie
even vith a complex set of modes vould be recognizable
and interesting. Very possibly, if Tovnes and Peter had
discussed the question directly, they vould have reached
some sort of agreement. None of us doubted that some
good method of mode selection vas highly desirable.

I began to think of these modes in terms of the
vaves of the Debye picture, that is vaves traveling in
different directions inside the resonator and having
different vavelengths. The range of vavelengths vas
limited by the bandvidth of the amplifying atoms. Nov,
to reduce the number of directions that vould be accept-'
able in the instrument vas not so easy. I thought for
avhile that perhaps there might be certain directions
in vhich the light could come out of the box, as there
is in a Fabry-Perot resonator, and that the output might
be an array of beams like the Laue spots of the x-ray
diffraction camera. I thought at one time of replacing
the vails of the box by diffraction gratings ruled so
that they vould only reflect light veil for a particular
angle of incidence and that only vaves coming in this
right direction vould be properly reflected.

Having advanced this far, around the beginning of
February 1958 I vrote dovn my ideas about optical masers
in my notebook. Of course many very vise scientists
vill tell you that any scientist vorth his salt care
fully records all observations, calculations and concepts

331

126 SCHAWLOW

in his laboratory notebook. However, I fear that I do
not qualify, because in seven years at Bell Telephone
I had not yet filled one notebook. Indeed my ex
perience had been that the only valuable calculations
and data were those that I took on scraps of paper.
Whenever I thought I had things in sufficiently good
order to record them in the notebook it turned out that
I had overlooked something and that that particular work
was essentially worthless. However, I did write down a
number of pages of thoughts about optical masers. They
included some calculations on potassium and the re
ordering of the equations and some of the ideas about
possible structures, even though I was not at all con
fident that the problem of mode selection was solved.
Even though I had never tried to patent anything, I
asked Solomon L. Miller to read and witness these notes,
on January 29, 1958. Miller had been one of Townes '
graduate students when I was at Columbia University and
had a laboratory near mine at Bell Telephone Labora
tories. He was certainly well able to understand the
discussion in my notes and so indicated when he signed
them. I was a bit startled, Just a few days later, to
learn that Miller had left Bell Labs to go to IBM.
Perhaps that had something to do with my never writing
any more ideas in my notebook.

But indeed I did get a good idea very soon after
writing these notes. I realized that if we took liter
ally the Debye picture in which the various modes were
waves having different lengths going in different di
rections, it could suggest a way to select one, or at
most a few of these modes. If a wave started from some
where near one wall of the resonator, it would reach a
different place on the far wall, depending on its di
rection. If, therefore, most of the far wall were
eliminated so that only a small patch remained, the wave
would only be reflected if it were going in the right
direction to reach that small patch of wall.

Thus we could reduce the large box to just two
small mirrors facing each other at the ends of a long
column of excited atoms. This arrangement would serve
as a good resonator for waves which travel nearly
straight along the axis Joining the mirrors. A wave
with any other direction would soon move sideways enough
to miss the small end mirror, and thus would be lost.

It was clear to me then that this resonator could
not hold any wave unless its direction of propagation

332

FROM MASER TO LASER 127

vas inclined to the axis by less than the angle sub
tended by one mirror at the position of the other.
Townes pointed out that this structure would be con
siderably more selective than that. Waves were expected
to bounce many times back and forth through the amplify
ing medium. Only a wave traveling quite exactly along
the axis would remain in the amplifying medium long
enough to attain a high intensity by stimulating emission.

This simple reasoning convinced us that we had
found a structure which would really strongly favor the
growth of a few selected modes. It was also apparent
that the output through one of the partially-reflecting
mirrors would be a highly directed beam, more or less
approximating a plane wave. We were also satisfied that
we kaew of at least one substance in which we would be
able to excite enough atoms for optical maser action.
However, it would take an uncertain time to build one,
and unexpected experimental problems might well be en
countered. We were aware that, during the three years
which it took to construct the ammonia maser, some of
the ideas had been discovered and published by others.
There were many more workers in the field by 1958. Al
though we were not aware of any direct competition and
did not particularly try to hurry, it seemed best to
publish our conclusions without waiting for experimental
verification. During the spring months we worked most
ly on writing the manuscript.

Before submitting the paper for publication, we
were required to circulate the manuscript to our
colleagues at Bell Telephone Laboratories for technical
comments and to the patent department to see if it in
volved a patentable invention. Several people, parti
cularly some of those most expert in microwave waveguide
theory, were skeptical of the reality of our modes and
the proposed method of mode selection. They wanted to
see a more complete calculation with rather precisely
defined boundary conditions, which was done only later,
in I960, by A.G. Fox and T. Li. We did, however, add
some paragraphs to our paper, in the hope of making the
mode frequency and selection argument more complete and
clear. There was some worry that there might be some
modes of the resonator with longitudinal field components,
as are found in microwave resonators. However, in a
resonator like ours, the wave travels many thousands of
wavelengths from one mirror to the other, and must be
have much like a wave in free space, and so must be
largely a transverse wave.

333

12 8 SCHAWLOW

The patent department was, at first, quite un
interested in the idea. I suppose that it appeared to
be remote from the needs of the telephone industry and
perhaps they did not believe it would work or that if
it did it would be very useful. However, largely at ^
Townes 1 insistence they did prepare and file an appli
cation for a patent. It was issued rather speedily, in
March, I960. Our paper was submitted for publication,
in August of 1958, and was published in the Physical
Review in the December 15 issue of that year.

The paper did arouse a considerable amount of^
interest and a number of laboratories began searching
for possible materials and methods for optical masers.
Townes, in his own group at Columbia, began efforts to
construct a potassium optical maser, working particular
ly through two graduate students Herman Z. Cummins and
later Isaac Abella. They were Joined for a time by
Dr. Oliver S. Heavens who is now Professor of Physics
at York University in York, England and who was even
then a world renowned expert on highly reflecting
mirrors .

We were of course aware of other possible materials
for optical masers. One of these was cesium vapor.
Cesium had the additional advantage that it could be
pumped by a strong spectral line from a helium lamp,
which happened to coincide with one of the cesium atom's
absorption wavelengths. This coincidence had been
noted in 1930 by C. Boeckner and mentioned in A.C.G.
Mitchell and M.W. Zemansky's book Resonance Radiation
and Excited Atoms (Cambridge University Press, 193 1 *)
We noted in our paper that a cesium infrared maser could
thus be pumped by a helium lamp. This kind of a laser
was constructed and successfully operated by S. Jacobs,
G. Gould, and P. Rabinowitz in 196l . Thus by 1958 we
knew a number of gases suitable for optical maser action,
although we could not be sure which would be easiest.

Being at Bell Laboratories, I had been pretty
thoroughly indoctrinated to believe that anything that
you can do in a gas can be done in a solid and can be
done better in a solid. I therefore began to explore
the possibility of solid optical maser materials.
Albert Clogston, who was my immediate boss at Bell
Laboratories, had encouraged my interest in optical
masers and now encouraged me to, if I wished, drop super
conductivity entirely and begin studies of possible
optical maser materials. On the other hand, nobody ever

334
FROM MASER TO LASER 129

suggested that we try and organize a group to build an
optical maser. Anything I did I would have to do my
self. There was a nearly invariable custom in the
physical research department that each man was to be an
individual scientist, and not an assistant to anyone
else .

About the optical properties of solids, indeed my
ignorance was quite total. However, even before our
paper was published I began to learn a little bit. One
thing that impressed me was that some materials such as
ruby had broad absorption bands and narrow emission
lines. Thus we were able to say in our 1958 paper that
"The problem of populating the upper state does not have
as obvious a solution in the solid case as in the gas.
Lamps do not exist which give Just the right radiation
for pumping. However, there may be even more elegant
solutions. Thus it may be feasible to pump to a state
above one which is metastable. Atoms will then decay
to the metastable state (possibly by nonradiative proc
esses involving the crystal lattice) and accumulate
until there are enough for maser action. This kind of
accumulation is most likely to occur when there is a
substantial empty gap below the excited level."

When writing that, ruby seemed like a tantalizing
possibility because it did glow so brightly almost no
matter how you excited it. Several people about that
time had become interested in the optical emission from
ruby including Saturo Sugano and Y. Tanabe and their
associates in Japan, Irwin Wieder at the Westinghouse
Research Laboratories, and Stanley Geschwind at Bell
Laboratories. But ruby seemed also to present a very
serious difficulty. The transition for the only strong
fluorescence lines were absorbed by unexcited atoms in
the same material. That is, they were resonance lines
and so the atoms could both absorb and emit the same
wavelength. Thus one would start out with the dis
advantage that initially all the atoms would be ab
sorbing, so that half of them would have to be excited
before any amplification at all could be obtained. With
out doing any calculations this really seemed like too
much of an obstacle to overcome, although there might be
some way because of the broad absorption bands for
pumping. Several people made measurements on the
fluorescence efficiency and strangely enough they all
gave estimates ranging from 1 to 10 percent. I now
think they were all trying to be conservative, but if
we had done a calculation and believed their figures we

335

130 SCHAWLOW

would have confirmed our prejudice that it was not
possible to obtain optical maser action in the resonance
lines of ruby. But I thought that perhaps there might
yet be some way, such as by splitting the energy levels
in a large magnetic field so that one sublevel at least
would be empty at low temperatures.

How was it that so many people at nearly the same
time began to study the optical properties of ruby?
Well, the one reason was that there had been an advance
in the understanding of crystals related to paramagnetic
resonance studies which could carry over into the optical
spectra. The dominant influence in my case and perhaps
in some others, was that ruby was being used in micro
wave masers. It was possible to visit Joe Geusic or
others at Bell Labs and find a drawer full of rubies
from which you could easily borrow samples. So much was
my practice to borrow samples that I remember a year or
so later that George Devlin marked on one of the spectra
"ruby ALS bought!," because up to then I had been most
ly borrowing .

One advantage of all this interest in ruby was that
crystals had been ordered and were available and with
various concentrations of chromium in aluminum oxide.
Although I did not think that ruby was going to be any
use for an optical maser material, it was interesting
because it seemed to have a fairly simp" :pectrum,
which according to the theory should ha .:ad Just two
emission lines at low temperature along t.h some bands.
Indeed at the very lowest temperatures it should have
only one emission line. In actual fact, as had been
shown many years ago by a number of experiments and most
thoroughly by Otto Deutschbein in 1932 and by S.F.
Jacobs and G.H. Dieke in 1956, there were very many
lines in the spectrum of ruby. I thought naively that
these extra lines might be due to the int'eraction of the
chromium ion with the crystal lattice vibrations and
that if we studied them it would give us some information
about the crystals. It also seemed interesting to look
at the c'rromium spectrum not only in aluminum oxide but
in the related gallium oxide which Joe Bemeika could
grow as small crystals with various concentrations.

I had at that time a Gaertner wavelength spectro
meter, a very simple student-type instrument which I
had bought when I first went to Bell Labs thinking that
it could be used for measuring thickness of thin metal
films. Darwin Wood was in charge of spectrochemi cal

336

FROM MASER TO LASER 131

analysis and he could make available some time on his
spectrographs and indeed collaborated with us on some
of our early studies.

I have mentioned George Devlin, who vas my tech
nician during most of my years at Bell Labs. I had
hired him even though he had very little formal train
ing and really a rather poor high school education. He
had, however, been a champion model airplane builder
and it was evident that he had an attractive personality
and a quick mind. It turned out to be a very rewarding
association. For Devlin, although he was almost complete
ly nonmathematical , had a real physical insight as well
as skill in designing, building and operating -equipment .
Perhaps one of his most valuable characteristics, was
that he did not have any great preconceptions as to what
the data should be. Several times, he pointed out to me
small effects which I would have dismissed as noise but
which he insisted were real and turned out to be inter
esting. One of these was that when we were looking at
various samples of gallium oxide crystals with various
concentrations of chromium, he noticed that the satel
lite lines, that is the extra lines to the red of the
strong R-line, were different in different samples. That
was all I needed and I immediately Jumped to the- con
clusion that these lines were not due to the crystal
vibrations but rather to pairs of chromium ions. The
probability of a given ion having a near neighbor in a
particular crystal ion position was going to be propor
tional to the concentration of the ions in the crystal.
At low concentrations such close neighbors would be
very unusual and at high concentrations they would be
common. This of course would also be the explanation
for the extra lines in ruby. Darwin Wood and I in
vestigated this point more quantitatively, collaborating
with Albert Clogston on the theoretical aspects, and we
published a note on the pair spectra in the summer of
1959.

However, one of the most interesting features of
this pair spectrum was that it could produce a large
splitting in the ground state of the chromium ions
which the crystal field alone could not do. Thus in
stead of having a single or a very narrowly split ground
state the splitting could be large enough that at low
temperatures some of the higher levels of the ground
state would be empty. This was what we thought we
needed for an optical maser. We really felt that if we
were to get optical maser action we had to give ourselves

337

132 SCHAWLOW

every advantage and that is why we had not seriously
considered the theoretical possibility that we could
empty out the ground state by pumping. I presented this
dark red ruby as a possible laser material, which would
oscillate in the satellite line at 7009 or TO^lA or
perhaps both, at the First International Quantum Elec
tronics Conference in September of 1959- In emphasizing
the advantages of the broad pumping bands in ruby and
the four-level system made possible by the exchange
coupling in dark ruby, I said briefly that the R lines
were not suitable for laser action. Of course, it
turned out later that both sets of lines can be made to
lase .

The proceedings of that conference, including my
talk, were published very quickly and issued in February
of I960, by the Columbia University Press. This is one
of the very few occasions when I remember exactly when
I wrote a paper. I had promised a manuscript by the
time of the meeting, but as so often happens other
things had prevented it. Therefore, I stayed at home
for the first two days of the three-day meeting, wrote
the paper and then came and delivered my talk on the
third day.

In that particular paper, I also described rather
concretely the structure of an optical maser in the
following words -- "The structure of a solid-state
maser could be especially simple. In essence, it would
be Just a rod with one end totally reflecting and the
other end nearly so. The sides would be left clear to
admit pumping radiation."

Well, if we knew the material and the structure,
why not do it? Now, when we know that construction of
a laser can be so easy, it is hard to give a convincing
answer to that question. But when we did not know how
to assess the difficulties and since it had never been
done, we believed that they might be formidable. For
example, no solid, and especially not dark ruby, is free
from variation of refractive index caused by strain.
Thus if a plane wave started out at one mirror and was
amplified as it passed down the rod, it would be dis
torted beyond recognition before it could reach the
other end and would not return nicely to the first
mirror. Nevertheless, I did manage to find from Bill
Mims, who was working on microwave masers, a rod of
dark ruby. And as early as December 1958 I had the ends
polished flat and parallel. I still have the order to

338

FROM MASER TO LASER 133

have this done at Laboratory Optical Company. However,
I did not acquire flashlamps and merely tried this half
heartedly with a General Radio Strobotac which I had
bought for measuring fluorescence lifetimes. This was
not enough power and nothing happened. One other reason
I did not push more agressively on it was that I was not
sure Just how cold the crystal would have to be to empty
the lower state of the optical transition. And besides,
there were too. many interesting things to do in studying
the spectrum.

But others were active. At Bell Labs, Ali Javan
had conceived the idea of a helium-neon maser making use
of transfer of energy from metastable helium atoms
produced in a gas discharge to particular excited levels
of neon atoms. Actually, I had heard the idea of using
a gas discharge even before we wrote our first paper.
Willard S . Boyle at Bell Labs had mentioned this possi
bility but he did not explore it seriously. He in fact
described it in the context that processes in a semi
conductor were similar to those in a gas discharge, and
that it would be interesting to try and find a semi
conductor analog of a gas discharge and that might pro
duce population inversion which would permit optical
maser action. Indeed Boyle has a patent on semicon
ductor lasers. We did not mention this idea in our
paper although both the gas discharge and semiconductor
possibilities seemed real, because these were Boyle's
ideas and not ours and it was up to him to publish them,
but he did not do it.

Ali Javan, however, did work out in some detail the
properties of a particular system and he published a
theoretical analysis in 1959- John Sanders from Oxford
who visited Bell Labs in 1959 for eight months or so had
another proposal using pure helium. People objected to
Sanders' scheme in that the lower level would not have
a short lifetime because of trapping of the radiation
which was supposed to empty it, but there were objections
in nearly everything anyone proposed and Sanders did
spend some time trying it out. However, he had to re
turn to England before any real conclusions were reached.

Javan, whom I had known as a student with Charles
Townes at Columbia and later as a postdoctoral worker,
was and is an extremely ingenious and able scientist.
His enthusiasm attracted others, most particularly
Donald R. Herriott and he was able to arrange for the
Laboratory to hire William R. Bennett, Jr. They made

339
131* SCHAWLOW

detailed studies of the processes in the gas discharges
and Herriott developed optical components of great
precision and quality for a helium-neon gas discharge
optical maser. This all took considerable time, and in
deed the research management at Bell Labs became con
cerned whether this was all a waste of a rather con
siderable amount of money or whether there was indeed
some hope in it. I remember people went around and
asked various opinions, but since these opinions were
quite uniformly optimistic, the research was continued.
But Javan and everyone else believed that the conditions
for maser action in gases might have to be quite special
as there are many processes tending to restore thermal
equilibrium. I don't think anyone realized, as we now
know to be true, that nearly any gas will lase if ex
citation is violent enough. Indeed no one even con
sidered looking at pulsed gas discharges until con
siderably later. Perhaps that was because of the pre
occupation with communications around Bell Labs, for
which a continuous laser seemed the only really inter
esting one. Indeed that was another obstacle which de
tracted from my pursuing pulsed laser operation in ruby.

Around the same time, C.G.B. Garrett and Wolfgang
Kaiser, both of whom had worked previously on semi
conductors, became interested in trying to develop a
solid state optical maser. They were, very reasonably,
attracted to the rare earth compounds and transparent
crystals which, as we had noted in our paper, give strong,
sharp fluorescent lines. With these materials, four
level systems with any empty lower state would not be
hard to find, but they do not have the broad pumping
bands which make ruby so attractive. Any incoherent
lamp used to pump them is likely to be largely wasted
because only small portions of its output spectrum can
be absorbed by the rare earth ions.

At TRG , Inc. Gordon Gould and other associates in
cluding Richard T. Daly had an Air Force contract to
work on optical masers which was, at least in part,
classified. They invited me to visit and give a talk
in the spring of I960, and we exchanged ideas about work
on spectroscopy of rare earth ions of the sort that
might be useful for optical masers. However, everything
we discussed presented formidable problems and an
operating laser did not seem close.

Sometime early in I960, we heard from one of Bell
Labs management that Hughes Aircraft Research Laboratory

340

FROM MASER TO LASER 135

in Malibu was also working on optical masers. This
point did not register very sharply, because I did not
know the people there at all well and did not believe
that they had anyone with any optical experience. Nor
did I know about the article which was published by
Harold Lyons in the Hughes news magazine in which the
use of a ruby as a three level maser material was pro
posed. T.H. Maiman's name was familiar from work he
had done on ruby microwave masers, including a paper at
the Quantum Electronics Conference.

I spent the spring semester of I960 at Columbia
University as a visiting associate professor. I had
been asked to do this because Townes was away at the
Institute for Defense Analysis and it seemed good to
have someone knowledgeable around in case his students
had difficulties between his weekly visits, and also to
teach courses. It was not possible for me to move to
New York and so I commuted there daily, spending half a
day or so at Bell Labs every week. This was an ex
hausting ordeal and I ended up the semester quite ill
with a succession of colds and an infection which took
weeks to clear away. But during that spring, I received
a paper from Physical Review Letters to referee. In it,
T.H. Maiman described some experiments on excitation of
ruby by a bright light or flash and made quantitative
measurements on the fraction of atoms excited. Maiman's
paper indicated that some percent of the atoms could be
excited, although it was not possible to tell from the
text whether he felt optimistic about being able to
produce about ten times greater excitation needed to get
more in the excited than in the ground state. I think
I suspected that he was interested in optically pumped
microwave masers. This manuscript was published in the
May 15, I960 issue of Physical Review Letters.

Late in June, there was a conference on Coherence
in Optics at the University of Rochester and some of
the Bell Labs people attended. They heard there, from
Malcolm Stitch, that Maiman had succeeded in operating
a ruby laser. This caused both excitement and puzzle
ment. Then, in early July there was a press conference
at which Hughes announced some information about Maiman's
attainment of stimulated emission in ruby. Accompanying
the press announcement was a photograph showing Maiman
with a rod, very much as I had described, inside a flash-
lamp. By that time, several people at Bell Labs were
working with flashlamps, and as there were not many
such lamps on the market, it was easily recognizable as

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136 SCHAWLOW

a General Electric FT-52U . Preprints of Maiman's
manuscript for publication were sent out to trad.
magazine?, and we obtained a copy from a magazine writ
er who came to Bell Labs to get our reactions and find
out what Bell Labs was doing. There was some ^pticism,
but it seemed quite convincing to me. So .many of he
people vho were trying to produce various kinds of
sta?e optical masers, began to -try to obtain laser ac-
tion in ruby.

Among them were Garrett and Kaiser, with some help
from Walter Bond who was developing techniques r
polishing and coating the crystals and also ^. Nelson
.* P T Collins These were in different departments

And so I went to ask Collins and Nelson about th.
progress. They felt that they needed better .Liagno
equipment than they had, in particular a better spectro-
grapS to tell what was happening. I had acquired a goo
spe?trograph for my research and so I Joined their effort
and they moved their equipment down to my spec '"graph.
Sithin a day or two they also had achieved laser action.
I remember they were using a General Elect 'J "-52 U
lamp which was rated at a maximum input of
from a 1*00 microfared capacitor. At this rated output,
the optical maser threshold was not achieved so they
raised in input voltage to U200 volts, 200 volts above
the manufacturer's rating, and their success was
attained It does not pay to be gentle when you have a
threshold effect! Lasers are nonequilibrium devices and
you sometimes have to be fairly violent to get suffi
ciently far away from equilibrium.

We did not start out by seeing the beam, but by
looking at an oscillograph showing the output of a
photomultiplier which received the light <ed
through the spectrograph. When laser action was achiev
ed there was a brief burst of much more intense light
than the fluorescence which was always emitted whenever
you .Ited the ruby crystal at all. The experiment was
of course quite improvised in many respects and the
briKht light from the flashlamp lit up the whole room
and made it very difficult to see what was going on
other than what the instruments told us. In fact, w
were not at all sure that the beam could be seen if
there were a beam. The light from the ruby is at a

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FROM MASER TO LASER 137

wavelength so long that the eye is two hundred times
less sensitive than in the green and the pulse lasts
only about one two-thousandth of a second.

But the first thing we could do was to find out
whether the ruby optical maser had any of the pre
dicted properties. One of these was that the light out
put should be more monochromatic, that is, should be
confined at a narrower band of wavelengths than that of
spontaneous emission. It should be directional and it
should be coherent, according to the theory of Townes
and myself. We set out to try and check these points.
The frequency spread could only be measured by flashing
the laser repeatedly, photographing the output on an
oscilloscope and changing the wavelength setting of the
spectrometer between successive flashes. This was some
thing of a problem, because the metal coatings on the
ends of the ruby rod, which were usually gold, did not
last long at the high intensities of the experiment.

Directionality, which we now can see very easily
by just looking at the beam, seemed hard to investigate
because we did not know whether we could see the beam.
The obvious way to do this was to put a camera focussed
for infinity where it could receive the laser output and
see whether the laser produced a small spot. A red
filter would have to be placed over the camera to screen
out the white light from the flashlamp. This was one
of the things we were going to get around to but it
finally began to be such an obsession with me that after
one sleepless night I came in prepared to tell everyone
that I was ready to fight to do this experiment next.
At this point everyone agreed without a fight, and we
found that the output was indeed focussed to a small
spot indicating a beam divergence of about a hundredth
of a radian, or a half a degree.

Now Mairaan had indicated in his paper that he would
not expect to get directionality because of reflection
from the side surfaces of the crystal. So we deliberate
ly left the sides of our crystal rough in order to mini
mize reflection from the side walls. Thus I really did
expect to get a beam and was gratified when it was ob
tained. It was a bit crushing a few days later, how
ever, when Garrett, Kaiser and Bond also observed a beam
Just as good as ours while the sides of their crystal
were polished. It was some months later before we
realized that the pump light is actually focussed with
in the crystal so that the degree of excitation is

343

138 SCHAWLOW

higher on the axis than it is near the walls. This
means that while amplification is feeing obtained near
the center of the crystal the outer parts are still
absorbing and so reflections from the side walls are
prevented .

In our photographs, we noticed that the spot had a
grainy substructure and so we found that the output
came in filaments. This helped to explain why the beam
was not even more perfectly directional than it was, as
some diffraction spreading is inevitable from these
small individual filaments. It also showed how laser
action could occur in solid substances that were known
to be highly imperfect. Indeed, study of the line-
widths showed the ruby crystal, which we used for our
earliest laser experiments, to be the most badly strainec
one I have ever encountered. But somehow there happened
to be some small paths over which light could find its
way from one end mirror to the other and if the gain
was high enough to overcome the diffraction losses in
such a thin column, lasing could occur.

Not very long afterward, Garrett and Kaiser took
the trouble to box in the laser so that the stray light
from the flashlamp could not reach the eye and light
could only come out through a hole at the end of the
ruby rod. They found, and everyone was excited to
realize, that the beam indeed could be very easily seen
as a bright red spot where it struck the wall. Maiman
also apparently observed the directionality about the
same time, for he submitted an abstract to the meeting
of the Optical Society of America and his paper was
presented at their meeting in October I960.

One day, George Devlin asked "Is there any sign of
hysteresis?" This would not be surprising because many
oscillators do tend to show an overshoot when oscillatior
starts or stops, and so we looked more carefully at the
oscilloscope trace. Fortunately, we had acquired a
Tektronics 555 dual beam oscilloscope in which one beam
gives a magnified picture of a small portion of the
trace displayed by the other beam. That is, we could
delay the second beam sweep so that it covered an inter
val of one hundred microseconds stretching between five
hundred and six hundred microseconds after the initia
tion of the flash. When we did, we could see that the
output was indeed quite spiky and instead of being a
burst of about five hundred microseconds it was in fact
a series randomly spaced, very intense, one-microsecond
pulses .

344

FROM MASER TO LASER 139

To prove the coherence was somewhat more difficult
experimentally. We knew that if the light coming out
of the laser rod was spatially coherent, we could tell
it by doing a Young's two-slit diffraction experiment
with the two slits being right in the plane of the laser
end mirror. Alternatively, we could have one wide single
aperture and observe diffraction maxima and minima in
the light coming out through this small opening. The
troubles were purely the experimental ones of laying
down the suitable patterns on the mirror and then having
the mirrors hold together long enough to do the experi
ment. We had not yet learned how to make dielectric
mirrors suitable for ruby laser operations. The single
aperture experiment was done first and the results
showed definite coherence across the width of the slit
which was about 50 micrometers by 150 micrometers.

Between the two groups at Bell Telephone Labora
tories we had amassed good experimental proof of the
predicted properties of an optical maser. We therefore
decided to submit a Letter for publication to Physical
Review Letters and we set a cut-off date beyond which
we would stop experimenting and finish the manuscript.
The single slit diffraction pattern was obtained before
the cut-off date but the double-slit was not until a day
or two later. The double slit results were therefore
submitted separately as a paper for oral presentation at
a meeting of the American Physical Society.

In writing this Letter we were concerned, of course,
to present our findings clearly and concisely. However,
we were afraid to use the title "optical maser," because
we had heard some reports that Maiman's letter reporting
his very important results had been rejected by Physical
Review Letters and we thought that the reason might be
because the editors of that distinguished Journal had
previously expressed a disinterest in further papers on
masers as being too concerned with devices for a Journal
at the frontier of physics. We therefore called the
paper "Coherence, Narrowing, Directionality, and Relax
ation Oscillations in the Light Emission from Ruby,"
and it was coauthored by R.J. Collins, D.F. Nelson,
W.L. Bond, C.B.G. Garrett , W. Kaiser and myself. I
learned much later that the reason for rejection of
Maiman's paper was quite different. The editor thought,
mistakenly, that it was Just a small extension of the
paper which he had published very recently, so that it
violated their rule against serial publication.

345
lUO SCHAWLOW

We also were concerned in that paper to be more
specific than Maiman had teen in describing Just exact
ly vhat we had used and had done. We therefore pointed
out that our laser rods had been five millimeters in
diameter and h . cm long even though this was about the
dimensions of the one shown in the newspaper photograph
of Maiman. We also specified that the lamp used was a
General Electric FT-52U. It was a year later that I
learned from Donald Buddenhagen that Maiman had in fact
not used the FT-52U in his experiments. It had been
shown in the press photograph because the lamps which
he had actually used were all broken by that time. In
a way that was fortunate, because the diameter of the
FT-521* was larger than the lamp which Maiman used
originally and had enough space in it to permit us to
put in a small Dewar flask and do experiments at lower
temperatures. We also learned much later that Maiman's
original crystal had also not been as long and narrow
as the one shown in the photograph, but that was not
published until some time later.

While this work was in the course of publication,
the Laboratories felt it important to demonstrate that
this work had something to do with communications which
is the prime task of the Bell System. They therefore
arranged to transmit pulses of laser light from the
Holmdel Branch of Bell Telephone Laboratories to Murray
Hill, an airline distance of about twenty-five miles.
There was known to be a direct line of sight between the
two laboratories, and there was a tower at Murray Hill
designed for microwave propagation experiments to and
from Holmdel. The experiment was carried out by Boyle,
Collins and Nelson and they were quickly successful in
not only seeing the beam by eye but photographing an
oscilloscope trace recording in detail the individual
pulsations or spikes which simulated a message that
might later be encoded on a laser beam. All this was
reported at a press conference soon after the publication
of our Physical Review Letter and received widespread
attention .

Meanwhile, I had been continuing my studies of the
dark ruby spectrum hoping to unravel the pair lines and
find out which ones belonged to which kinds of pairs of
chromium ions', nearest neighbors, second nearest and so
on. While that had not gotten very far, I came to
realize that the intensity of these pair lines was
really strikingly high. This indicated to me that they
were being pumped by the much more numerous isolated

346

FROM MASER TO LASER lUl

atoms. For example, if the concentration is a tenth of
a percent, then only one in a thousand of the chromium
ions will happen to have a neighbor at the adjacent
particular crystal lattice site. Yet, even though the
pairs could not be as numerous, the lines could be as
strong or even stronger than the lines of the isolated
ions. Indeed the absorption was relatively weak, as it
should be since paired ions are few, but the emission
was strong. This indicated that there was an even more
efficient method of exciting the pair lines than I ex
pected and, while I did not want to get into competition
with all those who were doing laser work, I finally
decided to try out the pair-line ruby laser. By that
time, in the fall of I960, I had acquired a power supply
and large flashlamps. The experiments were successful
and George Devlin and I found that laser action could
be obtained on either of the strongest pair lines
separately or simultaneously, with or without laser
emission at the R-line. This gave an interesting proof
that the 7009A 5 line and the TO^lS line came from distinct,
separate systems and that they are both separate from
the R-lines .

We had avoided the word maser in the paper which
Bell Laboratory people had sent to Physical Review
Letters. But it was apparent by that time, that not
everyone had understood that what we were talking about
was really coherent stimulated emission from atoms in a
resonator. I therefore decided that I would use the
term optical maser in this paper, even if that did mean
automatic disqualification from Physical Review Letters,
and sent it instead to the slightly slower but equally
reputable Physical Review. Physical Review Letters,
which provides quick publication of important new re
sults, has to be somewhat selective and must reject a
substantial fraction of the papers submitted if it is to
maintain a rapid publication schedule. Thus they can
sometimes apply somewhat arbitrary criteria like the
ban on masers which I supposed to be in effect. In
deed they must do so, because the initial discovery in
any field is often followed by a growing flood of
follow-up papers of gradually diminishing urgency.

However, somewhat to my surprise the paper ended
up being published in Physical Review Letters. It
happened because on the very same day that the paper by
myself and Devlin arrived at the editorial office of the
two Journals, they also received a paper by I. Wieder
and L.R. Sarles reporting stimulated emission from the

347

11*2 SCHAWLOW

pair lines in ruby . The first I knev of it was when the
Wieder-Sarles paper was sent to me to referee. I of
course said that it looked like good work to me. Then
the editors were faced with a necessity of treating both
comparable papers on a similar basis, either both in
Physical Review or both in Physical Review Letters and
they chose the latter. Thus both papers describing laser
action in dark ruby appeared in the February 1, 196l
issue of Physical Review Letters. Though the dark line
ruby laser has been confirmed, it has not been very much
explored because it has so far been operated at temper
atures considerably below room temperature.

Around the end of November, I960 I received a
telephone call from Mirek Stevenson, who had been a
graduate student with Townes at Columbia but was by that
time at the IBM-Watson Research Laboratory. He told me
that he and Peter Sorokin had obtained laser action in
two more substances, calcium fluoride containing di
valent samarium ions and calcium fluoride containing
trivalent uranium ions. Both of these materials opera
ted at cryogenic temperatures. Sorokir. and Stevenson's
results were already in course of publication in the
IBM Journal and appeared a day or so later. I remember
this event not only because it was one of the earliest
laser materials, probably the second and third laser
materials to operate, but also because a day or so
later when the IBM group announced their results I had
a telephone call from a reporter on the New York Times
asking for comments on it. Fortunately, by that time I
did know about it and I was able to help him get his
story straight. For instance, I suggested that it was
important for him to mention that the samarium and the
uranium ions were respectively divalent and trivalent,
and so it appeared in the New York Times story. At that
time, there were not as many good science writers as
there are now, and I have often been impressed by the
care in which the New York Times took to verify their
stories .

The other memorable aspect was that Stevenson told
me sometime later that he had accepted the challenge of
finding an optical maser material as a management prob
lem. Even as a graduate student he had been very inter
ested in investing and had been extremely successful in
the stock market. Subsequently he founded several com
panies, mostly in the field of investment and investment
research. But when presented with the problem of quick
ly constructing an optical maser he went at it by seeking

348

FROM MASER TO LASER ll3

out the sources of supply for each of the components,
that is the crystals, the flashlamp and the power supp
ly and assembling them from these sources so that the
experiment could be done in a hurry. This contrasted
somevhat with a do-it-yourself approach which most of
the others in the field followed. In this case it cer
tainly did pay off, because Garrett and Kaiser at Bell
Labs had been working on similar substances, but had not
been able to reach the point of getting suitable samples
installed in suitable equipment for tests. Undoubtedly,
Sorokin also played an important part in this work for
he has remained active and has indeed produced several
of the most important advances in laser physics since
that t ime .

The first public demonstration of an operating
laser was given at the Nerem Electronics Meeting in
Boston on November IT, I960, accompanying my talk.
Lewis Winner, who organized the Nerem Meeting had in
vited me early in the summer, before our experiments on
lasers had advanced very far. Fortunately, by the time
of the talk our results on the properties of ruby lasers
had been published and my colleagues agreed that I could
talk on them as well as about my own theoretical work.
A large ruby laser power supply was transported to the
hall and set up and we demonstrated that a bright red
flash could be produced and shown as a momentary bright
spot on the screen. We knew of nothing more spectacular
to do with it at that time.

A few months later, in January of 196l, George
Devlin and I were able to load an optical maser into the
back of a station wagon and drive it to Toronto for a
similar demonstration at a meeting of the Royal Canadian
Institute. But by June of 196l, Bob Ammons had built a
really portable ruby laser for Robert J. Collins to take
and display at the International Commission for Optics
Meeting in London. It used a commercial 200 watt-second
photoflash power supply and a small ruby rod with a
flashlamp and a little elliptical cylinder reflector.

During the same period, we were finding out some
things that these early lasers could do. Willard Boyle
showed that if the beam from a ruby laser was focused to
a small spot on the surface of an absorber, it would
vaporize a bit of that material, producing a white-hot
Jet. The temperature was so high that even the most
refractory materials, such as carbon, could be instant
ly vaporized. Boyle realized that lasers could then be

349

1UU SCHAWLOW

used for drilling holes and all sorts of materials proc
essing. Indeed within the next few years the Bell Sys
tem, in their Western Electric manufacturing division,
put lasers to use drilling holes in diamonds which were
to be used for wire-drawing dies. Again, Boyle did not
publish his results but I was able to use photographs of
one of these laser produced Jets to illustrate in artic
les which I wrote for Scientific American and the Solid
State Journal. Very soon people began to drill holes
in razor blades by focusing ruby lasers onto them. As
lasers were made larger, it became possible to drill
holes simultaneously through several razor blades
stacked one behind the other. Soon, someone suggested
that laser output power should be measured in Gillettes.'

From the beginning, writers of popular accounts in
the newspapers and some people in the military expected,
or at least hoped, that lasers would fulfill the old
dream of a death-ray. We had a good bit of fun with
this notion, which was so very far beyond the capabili
ties of even the largest lasers. I have often shown a
slide of our "death-ray countermeasur es , " which I made
at that time. It shows some suits of shining armor, of
the kind that knights used to wear. It was easy to cal
culate that an unprotected two hundred pound man could
be completely evaporated by about two hundred million
one-Joule shots from a typical ruby laser. If we could
deliver them at the rate of one per second, which was
rather better than we could do, he would only have to
stand there for six years. Still, it was obvious even
then that, once the principle was established, you could
expect ultimately to have very large sustained as well
as pulsed powers even though we did not yet know how to
achieve them.

But the problem remained of what one could do with
the small, expensive, heavy pulsed lasers then existing.
I moved to Stanford University in September 196l and a
few months later, in January of 1962 appeared on a local
television program called "Science in Action." I wanted
to illustrate my remarks with experiments but had only
one very small ruby laser not even big enough to drill
a hole in a razor blade. G. Frank Imbusch, who was then
one of my graduate students, suggested that we could
break a balloon with it and this was tested and found to
be possible. So Imbusch, Linn Mollenauer another student,
and I went to the studio. While I was rehearsing, the
students fixed the balloon with a cardboard base and
fins to look like a rocket ship, and positioned it in

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FROM MASER TO LASER lU5

front of the laser. I can assure you that I was much
concerned as to whether the thing would actually work or
not as the program was being broadcast live. Fortunate
ly, it did work and I began showing balloon-breaking
demonstrations. A year or so later, when I was in
Washington I spoke at a meeting of a group of the Inter
national Scientific Radio Union (U. R.S.I.) which happened
to meet at the same time as the Optical Society. We
were therefore able to make a demonstration with a large
ruby laser kindly provided by Trion Instruments (later
Laser Systems, Inc.). With this laser we could not on
ly break a blue balloon but we could let the light pass
first through a red balloon which did not absorb the red
light and was unaffected. This made it a more spectac
ular demonstration and showed that the color of the
light had something to do with it.

Still, the mind works slowly and it was not until
near the end of 19^3 when it occurred to me that the
balloon breaking experiment could be done with a dark
blue balloon inside a clear outer balloon. I realized
this as I was sitting with my son at the San Francisco
Zoo and watching other children carrying such balloons.
Of course such a demonstration is a very good illu
stration of something that could be done with a laser
and not easily in any other way, for the outer balloon
remained unharmed as it did not absorb the light. This
is also a good illustration of the use of lasers to
accomplish things that are at otherwise inaccessible
places, for example as. they are used for surgery on the
retina of the eye. To make the stunt more effective Ken
Sherwin, the technician with our research group, built a
small, portable ruby laser into the housing from a toy
ray-gun replacing the flashlight with which the toy had
been sold. I showed this first at the meeting of the
American Association for the Advancement of Science at
Cleveland in December, 1963. It was at that time, while
getting ready for the A.A.A.S. Meeting, that I realized
that laser erasing was possible although my little ray-
gun did not have enough power to erase more than a small
portion of a typewritten character.

The idea of a laser eraser appealed to me, not only
because it was elegant and useful, but also because it
pointed in quite the opposite direction to the thinking
of most of the efforts seeking laser applications. Here
was something that certainly could be done, and for
which there was a very large potential market. The only
problems were engineering and economic. In this it

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1U6 SCHAWLOW

contrasted sharply with attempts to make laser weapons
for which there were very large amounts of money, but
which no one knew how to do. Naively, I thought that I
could Just announce the idea of a laser eraser and
people would start to make them. When this failed, I
was urged to apply for a patent and did. It was appar
ent that nobody would make the substantial investment
to produce laser erasers without at least the protection
of a patent. The patent was finally granted in 1970,
but it may be that even that will not be sufficient to
overcome the economic obstacles to laser eraser use un
til suitable lasers are put into quantity production
for some other purpose.

Perhaps a little should be said about the atmos
phere surrounding the laser research and the way in
formation was communicated. The initial paper by
Townes and myself setting forth the requirements for an
optical maser and indicating the properties needed for
suitable materials did inspire both considerable inter
est and considerable skepticism. A number of very good
reasons were advanced why lasers might not ever work,
but some people did take the possibilities seriously
enough to work on them. When lasers were actually
demonstrated in I960, they did cause considerable ex
citement both in the popular press and in the scientific
and engineering community. Peter Franken had described
later, at a Symposium of the Optical Society of America
in 1971, the atmosphere at the Optical Society sessions

on lasers in the spring of 196l. " I recall now,

Just ten years ago on the nose, the first meeting of
any professional society on the laser. That was in the
spring meeting of 19&1 in Pittsburgh of this Society and
many of you may not have had the opportunity to be there.
Let me spend a minute and tell you what it was like:
sheer panic. At most meetings, Just to give you one
parameter, at most meetings people carry some cameras
and a man will show a slide, that is have a slide shown
at his request and you'll hear a few clicks. At that
meeting every time a slide was projected it was like the
sullen rumble of semi-quieted, semi-automatic fire. In
fact the high point in that meeting occurred during my
good friend Arthur Schawlow's lecture, which was a chalk
talk and he was talking about some of the puzzles and
mechanisms of the ruby laser. I recall a real key point,
I forget the rest of your talk, but the one point I
remember was your saying "We think that there are two
mechanisms operative in the spiking of the ruby laser,"
which was a big puzzle then. He went to the blackboard,

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FROM MASER TO LASER

picked up a piece of chalk and wrote down the number 1,
turned away from the blackboard and a dozen cameras
went off. This is the kind of panic that was going on

" I think Franken must have picked up a bit of

the excitement himself, for he soon borrowed a laser
and then with his associates Hill, Peters and Weinrich
achieved for the first time optical harmonic generation,
thereby ushering in the new and ever growing field of
nonlinear optics.

Not only were there scientists, but the early
laser meeting attracted a very large number of out
siders such as engineers in aerospace companies, who
were eager to garner any scrap of knowledge about these
new devices which they might incorporate in systems and
sell to the government. To me, the high point of this
general excitement over the prospects of lasers came at
the meetings sponsored at the Meeting of the Polytechnic
Institute of Brooklyn in New York in March of 1963
where it seemed that every few feet along the corridor
there was someone else asking me some question or other.
But then the excitement subsided as we expected and
people got down to the serious business of learning more
about the operation of lasers, finding new ones and
finding out what they could do. Moreover, the Tower of
Babel effect become more noticeable as individual
specialties within the laser field grew large enough so
that specialists from areas could hardly communicate
with others and indeed did not feel that it was neces
sary to do so very often.

What did I learn from all this? Many things, al
though no golden rule on how to do good research. To
every suggested maxim for guiding research, it is easy
to find a counter example. I have made many mistakes
and have seen my colleagues make mistakes either over
looking something which later seemed obvious or even
denying it. Yet a good forthright error is often a
stimulating thing as it challenges others to prove you
wrong. Many times new workers in the field seemed
quite foolish and they foundered initially but then
suddenly they were productive and producing their own
original contributions.

It also appears that there are times when one
should attack a problem head-on, seriously analyzing
the steps needed to attain a desired goal. This was
what Townes and I did in our analysis of the conditions
for an optical maser. At other times it is better to

353

SCHAWLOW

admit that ve do not know enough and Just sit back and
add fundamental knowledge, depending on both instinct
and logic to pick out potentially fruitful areas.

I also believe it is a good thing for some of us
should mix pure and applied research committing our
selves fully to neither. Thus Townes could, as he did
in the late l*0's, study deeply the processes in the
ammonia molecules as an example of the interaction be
tween molecules and electromagnetic fields. From this
study, he was able to obtain enough knowledge to invent
the maser. But if he had not had the practical inter
ests in finding out about applications, then that
particular piece of knowledge might not have ever found
its way to the mind of a person interested in generating
electromagnetic waves.

As one looks at the parallel histories of other
new fields of technology such as electronics or avia
tion, one cannot help realizing that lasers are still
in a very early stage of their development and that
many of the most exciting experiences of discovery are
st ill to come .

354

APPENDIX D

BEE TRANSACTIONS ON ELECTRON DEVICES. VOL ED-23, NO. 7. JULY 1976

773

Masers and Lasers

ARTHUR L. SCHAWLOW, FELLOW, IEEE

CHARLES H. Townes likes to tell the story of how he
invented the maser. In the spring of 1951, while he
was a Professor of physics at Columbia University and I
was a postdoctoral research associate in his laboratory, we
both attended the meeting of the American Physical So
ciety in Washington. As Townes remembers it, we shared
a room at the Franklin Park Hotel. He had several small
children and so was used to waking up early, while I, being
then a bachelor, was used to sleeping later in the morning.
When this happened one day, he dressed quietly in order
not to disturb me and went outside to enjoy the pleasant
spring morning in Franklin Park. There he thought about
the Office of Naval Research's Millimeter Wave Com
mittee which was to meet later that day. Two years of
meetings had so far failed to produce any major break
through in ways of generating radio waves shorter than the
centimeter lengths of the microwave region. At that point
he realized how to use molecules rather than free electrons
to generate these waves.

Townes had for several years realized that the sharp
resonances in atoms or molecules could act as radio circuit
elements. He had even obtained a patent on some of these
uses while at Bell Telephone Laboratories. He was also
aware that whereas ordinary molecules absorb waves, ex
cited molecules could amplify by the process of stimulated
emission. Lamb and Retherford [l] had remarked on that
possibility. But there seemed to be nearly insuperable
problems. Stimulated emission is the true negative of ab
sorption, and the same atoms or molecules can do either.
An atom in a lower energy state absorbs radiation, thereby
being excited to a higher state with more stored energy.
Amplification, on the other hand, occurs when an elec
tromagnetic wave interacts with atoms already excited to
upper energy levels and stimulates them to emit, thereby
enhancing the wave at the expense of the atom's stored
energy. Thus if there are more atoms in the higher energy
state, amplification will occur. But far more commonly,
atoms in the lower state are more numerous and so ab
sorption predominates. Indeed, in thermal equilibrium at
any temperature, there are always more atoms in lower
energy states than in upper ones, so that absorption is
commonplace and amplification by stimulated emission
is never observed. Thus even though the concept of stim
ulated emission had been introduced by Einstein more
than thirty years earlier [2], and its existence had been
confirmed experimentally by Ladenburg [3], the possibility
that it could be dominant seemed, to most scientists, so
remote as to be not worth considering.

Manuscript received March 5, 1976.

The author a with the Department of Physics, Stanford University,
Stanford, CA 94305.

Yet, radiofrequency and microwave spectroscopy had
blossomed in the 1940's for studying atoms, molecules, and
nuclei. With even a modest amount of radio power it was
easy to saturate an absorption and drastically alter the
numbers of atoms in the various quantum states. Indeed
one had to be careful to avoid distorting the spectra by
saturation. In the limit of high radio wave intensity, the
populations of the upper and lower states were equalized.
This process would not invert the population distribution
and produce the excess of upper state atoms needed for
amplification. Nevertheless radiofrequency resonance
studies showed that it was really possible to get far away
from equilibrium and to drastically alter the absorption.

There was one other clue. Purcell and Pound at Harvard
University [4], when studying nuclear magnetic resonance
found that the relaxation time of lithium nuclei in lithium
fluoride is extraordinarily long, fifteen seconds at room
temperature. When a magnetic field is applied to the
crystal, the nuclei of the lithium atoms, acting as the tiny
magnets that they are, precess around the magnetic field.
After a time, they exchange energy with the crystal's
thermal vibrations, and at very low temperature would all
settle down with their magnetic moments pointing in the
direction of the magnetic field. But at room temperature
a smaller fraction of the spins are thermally excited to the
higher energy state where they are opposite to the field
direction. Transitions between the two states can be in
duced by the absorption or emission of radio waves, and
ordinarily absorption predominates. Purcell and Pound
discovered an ingenious method for rapidly reversing the
spin direction, and this resulted in a momentary change
of the nuclear resonance signal from absorption to stimu
lated emission. They did not discuss the possibility of
amplification, and their effect was probably just a small
reduction in the losses of the circuit coupled to the crystal.
Indeed when Joseph Weber three years later in 1953 con
sidered seriously whether useful amplification by stimu
lated emission could be obtained, he discussed the mo
mentary gain from inverted spin systems and found it to
be very small.

But when Townes, on that spring morning in 1951,
thought about how to make an oscillator or amplifier using
stimulated emission, he thought about gaseous molecules
and, in particular, ammonia. He and his students had in
vestigated many aspects of this molecule which so strongly
absorbs microwaves. Then he realized that there was a way
to separate excited molecules which could emit microwaves
from unexcited absorbing molecules. If a beam of ammonia
molecules passed through a suitable electric field gradient,
the molecules would be deflected. Most important, mole
cules in these two lowest states would deflect in opposite
directions, and so they would be spatially separated. An

355

IEEE TRANSACTIONS ON ELECTRON DEVICES. JULY 1976

> *M1* ( I * *V Jl f*"^iT^Ty*^^T?iFi?SI*^l

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Fig. 1. Page from C. H. Townes' notebook recording the idea of the
original maser, 1951.

aperture at the end of the beam could then be positioned
to accept only molecules in the excited state, and to permit
them to pass into a cavity resonator.

The resonator would be tuned to the microwave fre
quency that the excited ammonia molecules could amplify,
and would greatly increase the coupling between the
molecules and an electromagnetic wave. Thus even a
moderate, attainable number of excited ammonia mole
cules could eive observable amplification. Moreover, if

excited molecules could be supplied fast enough, the rate
of stimulated emission would exceed the resonator losses.
Then a sustained time-coherent oscillator would be pro
duced from the stored energy of incoherently excited
molecules. Fig. 1 shows Townes' notebook entry recording
the invention.

Townes was optimistic that such a molecular oscilla
tor-amplifier would work and so he began to build one with
James Gordon, a graduate student, and Herbert Zeieer, a

8CHAWLOW: MASKRS AND LASERS

356

775

Ffc 2. C. H. Townes and T. C. Gordon with the second ammonia maser.
T. C. Wang on the right iUnd by the fint maer, 1954.

research associate. He did not feel it appropriate to publish
the ideas until they had experimental confirmation.
However, he talked about it quite widely and described it
in the Columbia Radiation Laboratory's Progress Report
The project was difficult and complex, but oscillations
were obtained from an ammonia beam device early in 1954
[6]. It was dubbed a "MASER" an acronym for Microwave
Amplification by Stimulated Emission of Radiation. This
first molecular oscillator produced a pure frequency mi
crowave output of about 10-" W at 23.87 GHz. The output
frequency was primarily determined by the molecular
resonance, so that its oscillation frequency could be used
as a frequency standard or atomic clock. As an amplifier,
it gave excellent low-noise performance but the narrowness
of the spectral lines, which made them so suitable for a
wavelength standard, implied a very narrow bandwidth
and little tunability. Fig. 2 shows Townes with students
J. P. Gordon and T. C. Wang with the first ammonia-beam
maser.

In the three years between Townes' conception of the
maser and publication of the first results, others had been
seeking the way to a molecular amplifier. In 1953, J. Weber
discussed the possibility of obtaining traveling wave am
plification and mentioned the possibility of vising nuclear
or electron spins [5]. However, he did not propose a par
ticular workable material or the use of a resonator. N. G.
Basov and A. M. Prokhorov early in 1954 proposed a
method of selecting out excited molecules in a molecular
bam, quit* similar to Townes' [7]. Later Basov and Pro
khorov suggested another possible method of obtaining
ctive molecules for a maser oscillator [8]. They pointed
out that if th atomic or molecular system had three or
more energy levels, a high-frequency electromagnetic field
could excite enough atoms for amplification. The high-
frequency field would be tuned to excite atoms from the
lowest to the highest of the three quantum states. If strong
enough, it would equalize the number of atoms in these two
itates and there would then be no more absorption but also
no amplification at that frequency. However, there could
be amplification at the frequency corresponding to a

transition between the upper and intermediate levels or
to that between the intermediate and lower levels. In these
three-level schemes, the output frequency would be lower
than that of the pumping field. Thus the three-level maser
did not offer a way to produce a shorter wavelength shorter
than that of the driving oscillator. Basov and Prokhorov
did not discuss a specific molecular or atomic system, and
the importance of this idea was not widely appreciated at
the time. Indeed, Townes had also recognized that masers
could be pumped by radio waves or even by light and re
corded that in his notebook in 1954, but had not bothered
to publish because it was not yet specific. Attention then
turned to electron spins in paramagnetic solids, which gave
strong microwave resonances which could be tuned by a
wide range by an applied magnetic field. Combrisson,
Honig, and Townes [9] were able to produce momentary
microwave amplification effects from donor atoms in sil
icon after suddenly inverting their electron spins by the
method of adiabatic fast passage. In the following year N.
Bloembergen [10], not knowing of Basov and Prokhorov's
1955 paper, independently discovered the three-level
pumping method and made a detailed proposal for
three-level, solid-state masers using nickel-zinc fluosilicate
and gadolinium-lanthanum ethyl sulfate. A few months
later, H. E. D. Scovil, G. Feher, and H. Seidel [11] obtained
continuous-wave maser amplification in gadolinium-
lanthanum ethyl sulfate with relaxation rates altered by
the addition of 0.2 percent cerium ions.

During the next several years, work on solid-state
three-level masers grew rapidly, and they were quickly
applied as sensitive low-noise preamplifiers for microwave
astronomy, satellite communications, and radar. New
materials were found, such as potassium cobaltr-chromium
cyanide by A. L. McWhorter and James W. Meyer [12],
and ruby by G. Makhov, C. Kikuchi, J. Lambe, and R. W.
Terhune. Both Bloembergen's and Townes' groups built
masers, the former using the potassium cobalt-chromium
cyanide and the latter using ruby. Consequently, when
Townes and Bloembergen shared the Liebmann Award of
the Institute of Electrical and Electronic Engineers in
1959, Townes had the ruby from his radioastronomy maser
made into a pin and presented it to his wife. On the way
home from the awards ceremony, Mrs. Bloembergen asked
her husband why he didn't do something like that from his
maser. All Bloembergen could do was reply "But my maser
was made of cyanide, dear!"

The rapid growth of maser research for low-noise am
plifiers and wavelength standards is strikingly shown by
the large number of papers, and especially the many lab
oratories represented, at the first Quantum Electronics
Conference in September of 1959. But already there was
competition from parametric amplifier*. Indeed one very
able scientist at Bell Telephone Laboratories decided that
masers had no future in communications, and so he
changed to working on parametric amplifiers.

While Townes and his itudenU had invented the acro
nym "MASER" from Microwave Amplification by Stim
ulated Emission of Radiation, very soon there was talk of
imilar acronyms for other, as yet unknown, devices. These

357

IEEE TRANSACTIONS ON ELECTRON DEVICES, JULY 1976

included RASER (Radio Frequency), IRASER (Infra
Red), LASER (light), UVASER (Ultraviolet), XRASER
(X Rays) and GRASER (Gamma Rays). Of all these, the
term LASER has subsequently become an accepted,
commonly used term.

FROM MASER TO LASER

When Townes first thought about the ammonia mo
lecular-beam oscillator in 1951, he had hoped that it could
be made to work on a rotational transition and generate
a wavelength in the half-millimeter region. But it had
turned out to be more convenient to work in the centimeter
region, where techniques were well known. So the problem
of using atomic systems to generate coherent radiation of
wavelengths shorter than the visible region remained un
solved when Townes and I turned our attention to it in
1957.

Although I had been a research associate at Columbia
University with Townes and had been excited by the maser
concept when I heard it in 1951, 1 did not work on it. By
then I had accepted a position in the physics research
group at Bell Telephone Laboratories. There I was hired
to work on superconductivity, and so that was what I did.
On weekends I worked with Townes on a book, Microwave
Spectroscopy, which was published in 1955. But by 1957,
I felt that the time was right to take a serious look into the
possibilities of extending the maser principle to shorter
wavelengths. I wanted to identify the difficulties and see
if solutions could be found for them. To start, I had only
some vague notions about using ions in crystals, which do
sometimes have fairly sharp resonances in the far-infrared
region. As Townes was then consulting with Bell Tele
phone Laboratories, 1 mentioned this to him. He also had
begun to think about the problem, and so we decided to
work on it together.

By that time (around October 1957), Townes felt that
it would be better to jump over the difficult far-infrared
region and try to build a maser in the near-infrared or even
visible, where so much more was known. Moreover, he had
some ideas about one particular possible system using
thallium atoms. He had made some notes and arranged to
send me a copy.

We both realized that incoherent light from a lamp could
be used to pump three-level or four-level optical masers,
analogous to these already in use at microwaves, if the
pumping light is bright enough. The fact that the pumping
light would be incoherent would not matter, any more than
the independent arrival times of the molecules of the am
monia beam to its resonator. In either case, the output
wave's coherence would be determined by the wave stored
in the resonator. The excited atoms would be stimulated
to emit radiation in phase with the stored wave.

The first problem was to see how much exciting light
would be needed and see if that would be obtainable from
any conceivable lamps. To begin with, it seemed best to
study atoms, and preferably fairly simple atoms such as
the alkali metals. The spectra of these atoms were already
quite well measured and understood, so that we could look
up the energy levels in the monumental Atomic Energy

Levels [14], a National Bureau of Standards Publication
edited by Charlotte Moore-Sitterly. Information on the
relative and absolute strengths of the various spectral lines
was much scarcer, but there was some help from the tab
ulation of L. Biermann in the Landolt-Bdrnstein Tables
[15]. Moreover, in the book Resonance Radiation and
Excited Atoms [16], by A. C. G. Mitchell and M. W. Zem-
ansky, there was a wealth of stimulating information about
the absorption and emission of light from alkali atoms.
Finally bright alkali-metal lamps could be made, and were
already commercially available, which emitted just those
wavelengths heeded to excite other alkali atoms.

Townes had the maser equation, which would permit us
to calculate how many excited atoms would be needed for
optical maser oscillation. This equation expressed the re
quirement that there must be enough excited atoms to
ensure that stimulated emission will supply energy to the
optical electromagnetic field faster than the field will lose
energy at the resonator walls. If the atom's oscillator
strength (a measure of the effective number of electrons
in a classical oscillator that would absorb or radiate as well
as the atoms at the particular wavelength) is large, a small
optical field will stimulate strong emission and only a few
excited atoms will be needed. If the oscillator strength is
small, as it is for "forbidden" transitions, correspondingly
more excited atoms will be needed for maser oscillation.
For a microwave gas maser, similar statements could be
made, except that the custom is to talk in terms of the
transition dipole moment rather than oscillator strength.

However, there is one important difference between the
optical and microwave cases. In the optical region, an ex
cited atom rapidly loses its stored energy by spontaneous
emission. Like stimulated emission, the rate of spontane
ous emission is also proportional to the oscillator strength.
Thus when the oscillator strength is high the excited atoms
decay quickly and must be replaced quickly. As a result,
the rate at which excited atoms must be supplied is inde
pendent of the oscillator strength. A forbidden spectral line
could be as usable for an optical maser as an allowed line

Our study of the maser equation revealed another in
teresting fact. A light wave in the resonator would lose
energy only at the walls, and would gain it by stimulating
emission as it passed from one wall to another. Thus it
would be helpful to make the device fairly large, very much
larger than one optical wavelength. Then the stimulated
emission could take place over a relatively long path be
tween wall reflections. The greater this distance, the less
the required density of excited atoms would be. Thus we
could reduce the power density requirement for the
pumping radiation by making the device larger.

With these considerations in mind, we made an estimate
of the pumping power requirements for an optical maser
using potassium vapor. The excitation would be supplied
at a wavelength of 404.7 nm and the output would be in the
infrared at either 3.14 or 2.71 tan. Assuming, for the cal
culation, convenient-appearing dimensions of 10-cm
length and 1 -cm crosssection, we estimated that a pumping
power of 1.2 mW would be needed. This seemed quite at
tainable, particularly since measurements by our colleague

358

SCHAWLOW: MASERS AND LASERS

Robert J. Collins (now at the University of Minnesota)
showed that outputs of up to 0.6 mW at the required
wavelength could be obtained from a single commercial
lamp. Brighter and bigger lamps could very probably be
made, and the dimensions of the structure could be
changed if needed.

Throughout these discussions, we had always thought
of a resonator which, unlike that of a microwave maser,
would be very large compared with a wavelength of the
radiation. This seemed to be rather obviously necessary,
for optical wavelengths are of the order of 1/20 000 cm.
Even if a tiny single-wavelength resonator could be fab
ricated, it would be too small to hold enough amplifying
atoms to overcome its losses. On the other hand, a large
resonator would not provide mode selection in the way that
a microwave maser's cavity does. A resonator of centimeter
dimensions would be capable of sustaining very many
different modes of oscillation, even within the small
bandwidth that the excited atoms could amplify. Martin
Peter, another Bell Laboratories colleague who is now at
the University of Geneva, particularly urged us to worry
about the problem of mode selection. He feared that the
output of an optical maser, even if it did oscillate, would
be a jumble of rapidly fluctuating modes of oscillation,
difficult to distinguish from spontaneous .radiation.
Townes felt rather that the problem might not be crucial,
since some perhaps moderate number of modes would have
lower losses than the others and would be most likely to
attain oscillation. While the oscillations in the favored
modes would fluctuate, they might well be quite distinc
tive. In all, he felt that lack of a better method should not
prevent going ahead with work on systems in which modes
were not well controlled.

At this point, I recalled that the resonant modes of a
large box can be thought of as waves traveling in various
directions between the walls of the box. Their wavelengths
would be restricted by the fairly narrow bandwidth of the
amplifying spectral lines. If we could restrict their direc
tions, we would drastically reduce the number of available
modes of oscillation. I thought of such things as having one
or more walls made up of diffraction gratings. Then I re
alized that the problem did have a simple solution. We
could remove almost all of the walls of the box, and leave
only two small mirror-like sections facing each other at the
ends of a long pencil-like column of amplifying material.
As long as the end surfaces were much larger than a
wavelength they would act as good mirrors and reflect
waves straight back and forth between them. A wave
traveling in a direction inclined at even a small angle to the
axis would miss the end mirror and be lost. When I told
Townes about this idea, he pointed out that the directional
selection would be even better than I thought, because the
amplification would permit a wave in the selected direction
to make many passes back and forth along the axis. An
off-axis wave might make one or two traversals but would
then be lost. Even though a detailed theory of the laser
resonator came considerably later, [17], [18] it seemed clear
that it would indeed select modes and produce a narrow
beam. These detailed calculations confirmed our conclu-

777

sion that the optical maser modes would be very nearly
plane waves.

Thus we knew we had a suitable structure and several
likely materials, and were convinced that an optical maser
could be made. Still, it had never been done and there
might be unforeseen problems. So we decided to publish
our analysis, and it appeared in the December 15, 1958
issue of Physical Review [19]. Townes then started a
graduate student, Herman Cummins on a project to try
and build an optical maser using potassium vapor. He was
later joined by another student, Isaac Abella, and by Dr.
Oliver S. Heavens, an English scientist who was already
well known for his work on optical properties and uses of
thin films. Considerable progress was made, but eventually
the successes of other researchers led the Columbia Uni
versity group to abandon work on potassium for easier
approaches.

Our paper on optical masers attracted considerable in
terest. Some people had serious doubts that it would even
be possible to build an optical maser, and some very
plausible arguments were advanced to prove that it would
not work. But a number of others seriously sought suitable
materials and ways to activate them. At Bell Telephone
Laboratories, W. S. Boyle mentioned the possibility of
using a gas discharge, but did not explore it seriously. He
was interested in semiconductors and carried his analysis
far enough to get a patent on a laser using recombination
radiation in a semiconductor. Independently, Ali Javan
considered using a gas discharge as the amplifying medium
for an optical maser, and published a specific proposed
method for using a mixture of helium and neon [20]. With
William R. Bennett, Jr. and Donald R. Herriott he set out
to build a gas-discharge optical maser. They made mea
surements of the excited state lifetimes and optical am
plification under various conditions. Then they designed
a laser structure with a discharge 1 m long, with extremely
flat, very highly reflecting end mirrors inside the ends of
the tube. John Sanders, visiting Bell Telephone Labora
tories for eight months from Oxford University, proposed
that an electrical discharge in pure helium might be used
[21] and made some efforts to test the idea.

For myself, I felt that it would be better to try to use a
solid material that could be optically excited to provide
optical maser action. This was very much in keeping with
the strong emphasis on solid-state devices in Bell Labo
ratories at that time. Although I knew nothing about the
optical and luminescence properties of solids, we had
mentioned the possibility of solid maser materials in our
1958 paper. So this study provided me with a good reason
to stop research on superconductivity and begin learning
about luminescent crystals.

One substance that was easy to start with was ruby, for
that material was being extensively studied for solid-state
microwave masers. Colleagues like Joseph Geusic had large
stocks of ruby crystals with various concentrations of
chromium ions in the aluminum-oxide crystal. I was in
trigued by the fact that strong sharp-line fluorescence in
the deep red could be excited by broadband light in the
green and blue region of the spectrum. Thus one could use

359

778

a broad-band pumping light to get relatively high gain per
excited atom of a sharp-line emitter.

However, in ruby all of the chromium ions are initially
in the ground electronic state. In emitting fluorescence
they return to this same state, and so the fluorescent light
can be absorbed by the unexcited ions. As a result, it would
be necessary to excite more than half of all the chromium
ions before optical amplification would exceed the ab
sorption losses. As no laser had ever been built I assumed
that it meant it must be very difficult to make one. With
out doing a serious quantitative analysis, I assumed that
one would require a fourth energy level far enough above
the ground state so that it would be nearly empty at the
operating temperature. Then as soon as any atoms were
excited to the upper state, amplification could be obtained
by stimulating them to emit to this empty final level. Be
cause the chromium ions in ruby lacked any such fourth
level, this did not seem a promising material for laser ac
tion.

Nevertheless the spectrum of ruby had some intriguing
features that seemed worth studying. The theory of the
spectra of ions like chromium in crystals was fairly well
developed by that time, especially from the work of S.
Sugano and Y. Tanabe in Japan [22]. The theory explained
only the two strong red "R" lines, but there are many
weaker lines within a few hundred angstroms further to the
red of these. These satellite or neighbor lines had been
known for about fifty years but had never been explained.
I thought at first that they might arise from the crystal
lattice vibrations and thus might give information about
those modes of vibration. However my technician, George
Devlin, noticed that the intensity of these lines varied from
sample to sample. We soon found, with the collaboration
of Darwin L. Wood, that the intensity of the neighbor lines
increased rapidly as the chromium concentration was in
creased. Thus we were convinced that the neighbor lines
arose from pairs of adjacent chromium ions, whose energy
levels were split by exchange interactions and we published
this finding in collaboration with Albert M. Clogston who
analyzed the theoretical aspects [21]. The lines were spread
out enough to give us hope that for near-neighbor pairs the
exchange-splitting might produce the fourth level we
wanted for the lower state of a laser. I pointed out the
possibility of getting laser action in dark ruby at one of the
satellite wavelengths, at the first Quantum Electronics
Conference in September 1959 [23]. We were encouraged
by the fact that at low temperatures a crystal of dark ruby
showed strong emission but little absorption at some of
these wavelengths. I even made a brief try at getting laser
action from a rod of dark ruby using a small flashlamp, but
that was not sufficient and I returned to trying to analyze
the neighbor-line spectrum of ruby.

Others made more serious attempts to achieve operation
of an optical maser. At Bell Telephone Laboratories,
Geoffrey Garrett and Wolfgang Kaiser investigated rarer
earth ions in crystals, looking for a four-level system that
could be energized by a bright lamp. At TRG, Incorpo
rated, a group including Gordon Gould and Richard Daly
studied both eases and solids.

IEEE TRANSACTIONS ON ELECTRON DEVICES. JULY 1976

Fig. 3. A. L. Schawlow with an early laser using a dark ruby rod, cooled
by liquid nitrogen.

But the first success was achieved by Theodore H.
Maiman at the Hughes Aircraft Company's research lab
oratory in Malibu, California. Maiman had worked on
microwave solid-state masers using ruby, and his laser used
a rod of pink ruby. A careful quantitative study convinced
him that a flash lamp could excite enough ions to give laser
action in pink ruby. He succeeded in demonstrating
stimulated emission in ruby and announced the results in
July, 1960 [24].

A number of scientists at Bell Telephone Laboratories
then pooled their resources and used optically-pumped
ruby crystals to confirm the predicted properties of laser
light [25]: directionality, monochromaticity, and coher
ence, as well as the high intensity that Maiman had re
ported. They also found that the laser flash was composed
of many short spikes, each lasting about 1 us.

Before the end of 1960, no less than four other lasers
were operated. Unknown to me, Peter Sorokin at IBM
Research Laboratory had also been studying four-level
ionic systems in crystals and, with Mirek Stevenson, he
obtained laser action both from trivalent uranium ions and
from divalent samarium ions in calcium fluoride [26], [27].
These were the first operating four-level lasers, but they
were very soon followed by another.

In November 1960, George Devlin and I tried again for
laser action in the satellite lines of dark ruby, using the
same rod as before but with a larger flashlamp (see Fig. 3).
We obtained oscillation at 701.0 and 704.1 nm, in addition
to the R line at 694.3 nm. At low temperatures, the satellite
lines had the lower pumping requirements as expected
since they were in a four-level system with an empty lower
level. At just about the same time, Irwin Wieder and Lynn
R. Sarles of Varian Associates also observed stimulated
optical emission in the satellite lines. By coincidence, both
our papers and theirs arrived at the Physical Review office
on the same day, December 19, 1960 [28]-[29].

But even before then Javan, Bennett, and Herriott had
achieved laser oscillation in their helium-neon electrical
discharge. Theirs was not only the first gas discharge laser,
but also the first continuous-wave laser [301. It operated

360

SCHAWLOW: MASERS AND LASERS

at several wavelengths around 1.15 tan in the near infrared.
In 1962, A. D. White and J. D. Rigden (31] found that the
tame gas mixture would oscillate at 632.8 nm in the visible
if mirrors designed for high reflectivity in the red rather
than infrared region were used.

By the end of 1960, five different kinds of lasers had
been operated. Pulses with peak power in the kilowatt
range had been demonstrated, as well as low-power con
tinuous operation. Already the range of wavelengths
spanned a range of 3.6:1, from ruby's 0.69 um to calcium
fluoride: uranium's 2.5 ^m. From then on the progress has
been increasingly rapid, with many new materials and
great extensions of the wavelength and power outputs both
continuous and pulsed. Quite marvelous and unexpected
things have been discovered. Yet I cannot help thinking
that even greater surprises may lie in the future. There are
so many things that we can imagine but cannot do eco
nomically or even cannot do at all. Quantum electronics
has attracted some of the keenest and most original minds
of our generation and they are continually making sur
prising discoveries. As a result, the subsequent history of
lasers is already much longer than these early beginnings.

At the time when we wrote our 1958 paper, Townes and
I were convinced thpt an optical maser could be made. But
we were surprised to find how simple the first lasers turned
out to be. Indeed many people since then have wondered
why lasers were not discovered twenty or thirty years
earlier, long before microwave masers. The techniques
were available then, but the ideas were not Every scientist
was trained to view the world as close to being in equilib
rium. Really radical departures from equilibrium would
be needed for stimulated emission to dominate, and that
seemed unthinkable. However in microwave and radio-
frequency spectroscopy, the quanta of radiation are very
small, and so molecules or nuclear spins can only absorb
small amounts of power before being strongly saturated.
Thus large departures from equilibrium were observed
without being sought, and researchers had to become very
conscious of stimulated emission. Thus minds were pre
pared to generate the clever ideas that led to masers, and
eventually to lasers. It was understanding and ideas that
were needed, more than techniques. Fortunately, scientists
were able to undertake wide ranging studies of matter
under unfamiliar conditions. They were thus led to new
insights and from that to- the radically novel devices we
now know as masers and lasers.

REFERENCES

[1] W. E. Lunb, Jr., and R. C. Retherford, "Fine itructure of the hy
drogen atom*, Part I." Phys Rev., vol. 79, p. M9, 1950 (remark on
p. 570).

779

(2] A. Einstein, "On the quantum theory of radiation," Phyt. Zeu , voL
18, p. 121, 1917.

[3] R. Ladenberg, "Investigation* on the anomalous dispersion of ex
cited gases; Part I, Test of the quantum-theoretical dispersion
formula," Z. Physik, vol. 48, p. 15, 1928.

[4] E. M. Purcell and R. V. Pound, "A nuclear spin system at negative
temperature," Phyi. Rev., vol. 81, p. 279, 1951.

[5] J. Weber, "Amplification of microwave radiation by substances not
in thermal equilibrium," Trans I.R.E. Profetiional Group on
Electron Device*, vol. PGED-3, June 1953.

(6] J. P. Gordon, H. J. Zieger, and C. H. Townes, "Molecular microwave
oscillator and new hyperfine structure in the microwave spectrum
of NH 3 ," Phyi. Rev., vol. 95, p. 282, 1954.

[7] N. G. Basov and A M. Prokhorov, " Application of molecular beams
to the radio spectroscopic study of the rotation spectra of mole
cules," Zh. Ektp. Theo. Fiz., vol. 27, p. 431, 1954.

[8] N. G. Basov and A. M. Prokhorov, "On possible methods of pro
ducing active molecules for molecular generator," Zh Ektp. Theo.
Fiz.. vol. 28, p. 249, 1955.

[9] J. Combrisson, A. Hpnig, and C. H. Townes, "Use of electron spin
resonance for a microwave oscillator or amplifier," Comptes
Renduet Acad Sci. Paris, vol. 242, p. 2451, 1956.
(10] N. Bloembergen, "Proposal for a new type solid state maser,'' Phys.

Rev., vol. 104, p. 324, 1956.
(11] H. E. D. Scovil, G. Feher, and H. Seidel, "Operation of a solid state

maser," Phyt. Rev., vol. 105, p. 762, 1957.

(12] A. L. McWhorter and J. W. Meyer, "Solid state maser amplifier,"
Phyt. Rev., vol. 109, p. 312, 1958.

(13) G. Makhov et a/., "Maser action in ruby," Phyi. Rev , vol. 109, p.
1399, 1958.

(14) Charlotte E. Moore, Atomic Energy Levels. VS. National Bureau
of Standards Circular 467 (1949, 1952, and 1958).

[15] A. Eucken and K H. Hellwege, Eds., Landolt-Bomstein Tables VoL
1, Atoms and Ions. Berlin: Springer Verlag, 1950.

(16) A. C. G. Mitchell and M. W. Zemansky, Resonance Radiation and
Excited Atoms, Cambridge University Press, 1934.

[17] A. G. Fox and T. Li, "Resonant modes in an optical maser," Proc.
I.R.E., vol. 48, p. 1904, 1960.

(18] G. Boyd and J. P. Gordon, "Confocal multimode resonator for
millimeter through optical wavelength masers," Bell Syst. Tech.
J., vol. 40, p. 489, 1961.

[19] A. L. Schawlow and C. H. Townes, "Infrared and optical masers,"
Phys Rev., vol. 112, p. 1940, 1958.

(20) A. Javan, "Possibility of production of negative temperature in gas
discharges," Phys. Rev. Lett., vol. 3, p. 87, 1959.

[21] J. H. Sanders, "Optical maser design," Phys. Rev. Lett., vol. 3, p.
86, 1959.

[22] S. Sugano sjid Y. Tanabe, "Absorption spectra of Cr 3 * in AljOj; Part
A Theoretical studies of the absorption bands and lines," J. Phys
Soc. Japan, vol. 13, p. 880, 1958.

[23] A. L. Schawlow, D. L. Wood, and A. M. Clogston, "Electronic spectra
of exchange-coupled ion pairs in crystals, ' Phys. Rev. Lett , vol. 3,
p. 271, 1959.

[24] T H. Maiman, "Optical maser action in ruby," British Communi
cations and Electronics, vol. 7, p. 674, 1960; Nature, vol. 187, p. 493,
1960.

[25] R. J. Collins et ai, "Ph Coherence, narrowing, directionality, and
relaxation oscillations in the light emission from ruby," Phys Rev.
Lett., vol. 5, p. 303, 1960.

[26] P. P. Sorokin and M. J. Stevenson, "Stimulated infrared emission
from triva'ent uranium," Phys. Reu. Lett., vol. 5, p. 557, 1960.

[27] P. P. Sorokin and M. J. Stevenson, "Solid-state optical maser using
divalent samarium in calcium fluoride," IBM J. Res. Develop., vol.
5, p. 56, 1961.

[28] A. L. Schawlow and G. E. Devlin, "Simultaneous optical maser ac
tion in two ruby satellit lines," Phys. Rev. Lett., vol. 6, p. 96, 1961

(29) I. Wieder and L. R. Sarles, "Stimulated optical emission from ex
change-coupled Ions of Cr+++ in AbOa." Phyt. Rev. Lett., vol. 6,
p. 95, 1961.

[30] A. Javan, W. R. Bennett, Jr., and D. R. Herriott, "Population in
version and continuous optical maser oscillation in a gas discharge
containing a He-Ne mixture," Phys. Rev. Lett., vol. 6, p. 106, 1961

[31] A. D. White and J. D. Rigden, "Continuous gas maser operation in
the visible," Proc. I.R.E., vol. 50, p. 1697, 1962.

361 APPENDIX E

NEVER TOO LATE - Communication With Autistic Adults

Aurelia T. Schawlow and Arthur L. Schawlow
849 Esplanada Way, Stanford, CA 94305

Proceedings of the NSAC (now Autism Society of America) National
Conference, July 1985

ABSTRACT

Two years ago, at the age of 27, our son was essentially without
speech and his only means of communication was with gestures. As will be
described, he is now able to communicate anything he wants to say, by
using a keyboard device.

INTRODUCTION

When our son Artie was small, he displayed the symptoms we now know
as autism. But even the name "autism" was only about a decade old then,
and few people knew it. Even if they did, there was no effective treatment
and no school classes for him. We sought help everywhere, and often we
thought that some time in the future something might be discovered or we
would find someone with ideas that would have helped him if we had
known it in time. But we made a conscious decision that we would at all
times do the best we knew, and not regret later what we did not know. We
kept on searching, and trying, and at last he has made progress at an age
when many parents are no longer struggling. After all, most of us keep
learning throughout our lives. Art was 55 when he bought his first
microcomputer (an Apple I!). So we are happy to report that it isn't too
late, and our son in his mid twenties has learned how to communicate.

CHILDHOOD AND ADOLESCENCE

He was very withdrawn and unreachable. From age eight he lived at
Clear Water Ranch, and from about 10 to 14, with Mrs. Grace Turner in a
6-boy group home in Cloverdale. Those were relatively good years for him
and he learned some living skills. Mrs. Turner brought him to Stanford for
some trials on Dr. Colby's talking typewriter, but he did not take to it.
At adolescence, people became afraid of him, because he was big and
strong and would have occasional tantrums, even though he never hit
anyone. Eventually we could find no place that would take him but the
state hospital, which promised various training and vocational programs.

362

But the promised programs somehow never materialized. Instead, they
drugged him with antipsychotics despite our vigorous protests. We kept in
close touch, with weekly visits, but he was too doped to do anything.
Eventually, when the adverse side effects of these drugs became apparent,
we obtained a court order of conservatorship, which specified our right to
approve his medical treatment, and the drugs were stopped. Years had
been wasted, and his behavior had deteriorated somewhat in the chaotic
and violent conditions of the hospital. But he was now much warmer and
responsive, and wanted to be with us.

SIGN LANGUAGE

A behavioral specialist suggested that we try teaching him sign
language, and we hired a sign language teacher to go in and work with him
at the hospital. He would sit at a table with her, and make signs for such
things as candies and cookies, and would receive a little of the named food
when he made the right sign. He also learned a few other signs, such as bed
and eat. In a way, this was a failure because few of the staff knew sign
language, so that he had really no opportunity to use it for any practical
purpose. In another sense it was very important, because for the first time
he would sit and work with someone who was trying to teach him.

HIS FIRST TEACHER

We also found a very good teacher, experienced with autistic children,
who was able to get him to recognize some letters on cards. She had Artie
make signs for words printed on cards. It was suprising to us that he could
do it at all, but sometimes could do it well. At other times he would just go
through his repertoire of different signs. The teacher also found that he
could even do beginning arithmetic by picking a number card for the sum
of two small numbers, e.g. 2+3=5. Unfortunately, she soon got a better job
and was not longer available. We tried other teachers, but he made no
further progress with them at all. He was glad to see them, and willing to
sit with them, but he was content to repeat the same simple things time
after time.

FINDING THE COMMUNICATOR

In December of 1981 we visited Stockholm for the Nobel
presentation. We met there with Karin Stensland Junker. She is the mother
of an autistic girl, whom she has told about in the well known book Child
in a Glass Ball. She is also a clinical psychologist. Dr. Junker told us about
a young man, age 24, who had been brought to her office. He looked
typically autistic, and just sat there rocking and apparently ignoring
everyone. Yet he had learned to communicate with a little device that
looked like a calculator. It had an alphabetical keyboard, and printed the

363

letters on a paper tape as they were typed. She asked him, for instance,
"May I have some of your tapes?" He replied, in Swedish of course, "No."
"Why not," she asked. "You can't read it when the sun shines" was his
reply. This device uses thermal printing, and the tapes do fade quickly in
sunlight.

This was exciting. How could Artie tell us something like that, even if
he understood it? He had no way. We must get one of these devices and
try it with him! But we didn't even know its name or who made it.
Eventually we found that it was a CANON COMMUNICATOR, and that there
was a distributor in Palo Alto, a mile or so from our house (2). We bought
one, but it was a total failure. He would hit just a few keys over and over,
like XXXXZZZZ, and would not type words. So we put it aside, and tried
other things.

ALPHABET CARDS

Each had a cutout into which the letter would fit. We would say the name of

the letter and the word illustrating it, as he put each one into the card.

TOUCH AND TELL

This device (3), made by Texas Instruments, uses a voice synthesizer
to ask things like "Show me the red letter G," or "Show me the small letter
r." We found that he knew the names of all the letters, lower case as well as
capitals. He could even answer when the voice asked for "the letter for
octopus," etc.

LOTTO CARDS

We had him match pictures to pictures, and then pictures to words. We
would print words on the back of cards, and have him match the word to a
picture, or even give us a word on request. Another way was to have him
put the words on the right picture on the board.

MAKING UP WORDS FROM LETTERS

We tried scrambling letters to arrange into a word, and he was able to
spell his name and some other familiar words that way. Then we had him
pick letters out of a box to spell a word.

READING BOOK

We obtained a child's book, the story of The Three Bears. Aurelia told him
that she had learned to read by underlining a word, wherever it appeared.
"Let's under line the word bear, wherever we see it." He was able to do that
right away. Soon, we found that he could pick out any word on a page of
that book. Even more surprisingly, he could pick out words from a
magazine page, even one as difficult as the New Yorker.

364

LETTER FROM THE RONNLUNDS.

We had obtained the address of the parents of the Swedish boy
who used the communicator, and had written to them asking how they had
taught him to read. Their letter described what they had done, and we
were much encouraged to learn that the way we were working with Artie
was rather similar to the way they had taught their son. Their letter is
reprinted in our article (1).

EPSON COMPUTER

At that time, Artie was living in a state hospital, and we could only
work with him on visits. Conditions at the hospital were such that it was
not practical to set up a computer and leave it there. However, the EPSON
HX-20 computer was introduced, and it was battery operated and hardly
bigger than a notebook. We found a way to program it in such a way as to
induce him to hit just one key on a keyboard. A short program in the BASIC
language would display on the screen a word, chosen randomly from a list
in the program. A dash was shown under each letter of the word. Then
nothing would happen unless he hit the right key to match the next letter
of the word displayed on the screen. When the word was complete, it was
printed out on the strip printer built into the computer. The first time we
tried it, he did it eagerly for more than an hour until the tape ran out, and
he stuffed the printer tapes into his pocket.

We tried to get him to use the computer to select an alternative, e.g.
steak or pizza, but without much success.

COMMUNICATION BOARDS

By this time it was apparent that he knew the alphabet, and could
recognize and spell some words. But he was not yet using words for
communication. An article about our work up to that point (1) was
submitted in August 1983, and concluded with "We are excited that our son
is not too old to learn and is making progress The spark is there. Can we
learn to fan it into flame, will it grow by itself, or will it fade
away again?" But a few weeks later, progress was so dramatic that we had
to write a postscript to the article.

USING WORDS TO COMMUNICATE

During the summer of 1983, a speech pathologist introduced us to
communication boards. These were cards or even sheets of paper, on which
words were printed. He could answer a question or choose something by
pointing to the appropriate word. With a communication board, he could
make a choice of foods, activities, or tools and materials for those activities.

365

The speech therapist thought that he might require pictures on the board,
but this was not at all needed.

Around the same time, we made word cards for foods, then colors,
etc, and had him put the cards on the object named. This, and the
communication board, gave him practice in recognizing words, and gave
him an opportunity to make choices by using words.

VOCAID

The VOCAID (3) is another Texas Instruments device, similar in
construction to the TOUCH AND TELL. However, it is programmed for people
who have lost their voice and need to transmit essential messages, like "I
AM COLD." Artie was able to use this immediately, and surprised us by
stringing together two phrases to make a sentence. For instance, once he
told us "I AM. ..UPSET." However, the range of choices is limited and he did
not use it much. When he moved to a group home, at first the VOCAID was
useful to let the staff know when he was upset or needed something.

RETURN TO THE COMMUNICATOR

Most of these activities took place on outings from the hospital to a
park. Afterwards we would finish with pizza and then ice cream. Art would
get cheese pizza, because that was what he preferred. But since Artie was
now making choices, we could let him choose what kind of pizza he wanted,
by pointing to one of the words printed on a sheet of paper. Indeed, he
unhesitatingly preferred sausage pizza. Then we had him confirm his choice
by reproducing the chosen word on the COMMUNICATOR. He was willing to
do this.

A few weeks later, one of these outings was finishing with ice cream
at a small shopping center. Then Artie waved his hand in a way that
indicated vaguely he wanted something in a particular direction. So, instead
of guessing, we took a chance and said "Come on out to the car and tell us
what you want, on the COMMUNICATOR." We didn't really expect that to
work, but he typed "SHOES," and indeed there was a shoe store there. So we
took him in and bought shoes for him.

AURELIA'S VISIT TO ARTIE on the following Monday.

Two days later, Aurelia visited Artie, and went through his usual
activities on the grounds of the hospital. But this time, she had him make
his choices of activities by typing on the COMMUNICATOR, rather than by
the communication board. Of course, these were all words he had seen
often. But at the end, she asked him where he would like to go for a snack.
He replied "GO TO MACDONALDS." "What would you like to eat there," she
asked. "HAMBURGER..COKE..ICE CREAM" were soon forthcoming. After that,
he wanted "PIZZA WHEEL" ( a nearby pizza parlor), and "SAUSAGE PIZZA."

366

This was really working, and so he asked for and got a visit to a steak
house for steak. It was getting late then, and she wanted to end the visit,
but he typed "STAY YOUR TIME WITH ME." Then he added, not just once
but three times, "I WANT TO GO HOME." So, although we were not ready for
a visit, he came home, and remained for three weeks while arrangements
were completed for a placement in a new group home.

THE STAY AT OUR HOUSE

We tried to see whether Artie would use the COMMUNICATOR
independently, and sometimes he would if he was especially eager. Most of
the time, he wanted a hand on his for reassurance and help. We decided
that getting his communications was more important at that stage than
forcing him to be independent, and indeed he still wants a reassuring hand
on his. We asked him when did he learn to read. He replied "WHEN I WAS
TEN YEARS OLD." "Who taught you?" "GRACE (Turner)." "Why didn't you
show it." "TOO HARD." "How is it that you can do it now," Aurelia asked. He
smiled sweetly and replied "I LOVE YOU." He told us that he liked cowboy
movies. "Why cowboy movies," we asked. "WIN THE WEST" was his answer.
We learned that he liked the color red. One evening, he really surprised us
by using the communicator to ask for "CHOCOLATE PUDDING."

We found that Artie could print some without the keyboard. We
learned this one day when Aurelia wrote down the list of tasks for the day.
He likes to do chores around the house, but one day he grabbed the pen
and printed VOTE. "Vote?" she asked. "VOTE WHAT WE MAY DO," was his
reply. Then he crossed one of the jobs off the list. He does some printing
now, but always wants another person's hand steadying the pen.

AT PARADISE SCHOOL

At first, many of the staff did not believe in the Communicator, and
did not use it with him. If someone tried half-heartedly, he would resist
and conceal by just typing ZZZYXXXX, etc. We persuaded some of them
to have him choose morsels of different foods with it, and they were able to
do that, but only a few of them advanced any further. Now, however he
does communicate fairly freely with several staff members, and with the
teacher who works with him twice a week. Sometimes he has used the
COMMUNICATOR to initiate things like "MAKE COOKIES."

We visit him nearly every week, and he tells Aurelia a lot of things.
We had noticed that the mother of the Swedish boy said that he never asks
questions. So, one night at dinner, Aurelia asked Artie if he would like to
ask any questions. His reply was a question: "WHY SHOULD I TYPE
QUESTIONS?" "Because there might be something you would like to know,"
she said. His next question was "DO YOU LOVE ME?" On being asssured that
she did, he asked "WHY CAN'T I LIVE AT HOME?" "Because there are things

367

you need to learn here," she said. Then he asked "WHY AM I NOT LIKE
HELEN (his sister)?" Again thinking quickly, Aurelia replied "Helen has a
job." "I CAN GET A JOB," he said. "You can when you have learned some
more," he was told. Since that time, he has often told Aurelia of his feelings,
worries, and hopes. He communicates that he very much wants to be
normal, and indeed anything that makes him feel more like a normal
person is a strong motivator.

ARITHMETIC

Art also programmed the EPSON computer to ask Artie questions
about addition, then multiplication and division. We found that he knew the
multiplication tables and could add, subtract, and divide simple numbers.

READING COMPREHENSION

We asked him questions about text on a page after reading it silently.
We found he could read even faster than we could, and we are fast readers.
He must have been catching things at a glance all these years, when he
never seemed to read anything.

THE TEACHER

Artie has been gradually revealing so many things he knew, that we
sometimes wonder whether he is really learning anything new. However,
we have found a teacher, not experienced but persistent, observant and
resourceful. At first, she -tarted on addition and he typed answers on the
COMMUNICATOR. After a few lessons, he gave some answers to questions,
in words and sentences.

She started on multiplication with flash cards for 2X2, etc, and he
seemed happy to work on that level. We told her that he already knows the
multiplication tables. The next week she said, "You're right, he does." He
told her that he did not know about carrying in addition, and she taught
him that. Subsequently he learned, very quickly, about multiplying large
numbers, long division, decimals and fractions, going through a grade level
in about 3 months of 2 lessons or less per week. He does some printing with
the teacher, mainly for answering questions. However, he has written some
letters to us, with a little prompting from the teacher.

OTHER PEOPLE'S RESULTS

Two young men in Ottawa, at the McHugh School (Stanley Tovell,
Program Director) have learned to communicate with a SHARP
MEMOWRITER, quite independently of our work. They are also using some
computer programs and one of them is doing reading and arithmetic at a
tenth grade level. Keyboards do not work for everyone in their classes.

368

A 35-year old man, living at Camarillo state hospital who had learned
to read earlier but was not communicating. His mother heard about our
article, and since then has gotten communication from him with a
typewriter. We learned at the NSAC Meeting that he is now using a
COMMUNICATOR.

THINGS THAT DID NOT WORK WELL

Texas Instruments Computer TI 99-44

We bought it about two months before Artie came home from the hospital,
because it had a very striking program for learning the alphabet. But it was
not practical to use at the hospital. Ly the time that he came home, it was
clear that he was much past learning the alphabet. We set the
microcomputer up at his new group home, and Artie did do some of the
arithmetic programs with one of the staff members there. He was also able
to handle the reading programs at the third grade level or so. The difficulty
was that he found them too slow, and did not want to wait for the
computer's response.

Voice synthesizers.

We tried both the VOTRAX TYPE 'N TALK and a borrowed voice synthesizer
in the $3000 price range, but he resisted them. He was with his mother
when Art was trying out the more expensive synthesizer. He told her "That
sounds silly. I could learn to talk with one of those, but I want to talk by
myself." As he always has, he occasionally says some words, but he is not
able to use them at will for communication.

THINGS WE HAVE LEARNED

You have to be interested in what he wants to say. It is important to
make each step easy and rewarding. He has a good long attention span, but
a short frustration span. His biggest problem seems to be an overwhelming
shyness, like stage fright, that makes him afraid to try things and to reveal
what he can do. Devices are very helpful, but the close, supportive, personal
interaction is essential.

CONCLUSION

Autistic adults can learn, just as normal adults can. It really is never
too late. As for how we feel, we can only quote the Bible story of the
prodigal son, and say that "our son who was dead is alive again."

NOTES

(1) The Endless Search for Help, by Aurelia T. Schawlow and Arthur L.

Schawlow, in Integrating Hoderately and Severely Handicapped

369

Learners: Strategies That Work, edited by Michael F. Brady and Philip
Gunter, Charles Thomas Publishing Company, 1985.

(2) CANON COMMUNICATOR is distributed by CANON U.S.A., and can be

obtained from medical supply companies.

(3) TOUCH 'N TELL and VOCAID are products of Texas Instruments. TOUCH
'N TELL is found in toy stores, and VOCAID in medical supply stores.

370 APPENDIX F

INTEGRATING

MODERATELY AND

SEVERELY HANDICAPPED

LEARNERS

Strategies that Work

Edited By

MICHAEL P. BRADY and PHILIP L. GUNTER

With Linda Parnell, Technical Editor
A Foreword by Roger J. Blue

A Project of
The Association for Retarded Citizens-Tennessee

CHARLES C THOMAS PUBLISHER

Springfield WHO* U.1A.

WRITTEN 1983 PUBLISHED 1985

371

CHAPTER 1*

OUR SON: THE ENDLESS SEARCH FOR HELP

AURELIA T. SCHAWLOW AND ARTHUR L. SCHAXVLOW

Our son was born on March 21, 1956. That was about two weeks later
than expected, and more than two feet of snow had fallen in New
Jersey over the preceding weekend. There were some anxious hours, but
eventually the snow did end and roads were cleared in time for the trip to
the hospital. The birth was long and difficult, and was complicated by a
deep transverse arrest that the doctor, busy with another patient, overlooked
for several hours. But our son was so beautiful and lively; our first child! We
named him Arthur (after his father and paternal grandfather) Keith. We
have always called him Artie.

At the time. Art was a research physicist at Bell Telephone Laboratories
in Murray Hill, New Jersey, and Aurelia was choir director of the First
Baptist Church in Morristown. We had a new house in Madison, and Artie
was the center of our life. Before long, he was joined by two sisters, Helen,
born in July, 1957, and Edith, born in November, 1959. Artie seemed to us a
perfect baby, ahead of the books' predictions in physical development like
turning over, sitting up, standing and walking. Yet, if we had been more
experienced parents, we might have known that he was neither as demand
ing nor as responsive as most children. He was quick to learn things by
himself, but not at all easy to teach.

Around the age of one, he began to say a few words, but then he stopped.
He gradually became more withdrawn and often seemed content to amuse
himself by listening to music or playing with toys.

Becoming concerned, we began what was to become an endless search for
help. An old friend, a distinguished European-born neurologist, told us
that our son had "a mathematician's personality" and would eventually start
to talk. At that time. New Jersey had no medical school. Even though we
lived in an affluent suburban area, there were few specialists familiar with
the more unusual childhood conditions. We did find a pediatric neurologist

The Schawlows we parents of an autistic ion. Ankur Sckaelov received his Ph.D. from the University
of Toronto. He currently is Professor of Physics at Stanford Univenity. He received a Nobel priie in
Physics in 1901 for his contributions to the development of laser spectroscopy. Aunln Skarlow received her
M.A. from Columbia and is a musician, singer, and choral conductor.

372
6 Integrating Moderateiv and Severely Handicapped Learners

who, although extremely busy, eventually did examine our son. She decided
that he had petit mal epilepsy and prescribed a drug for that. Almost
immediately, it was apparent to us that the drug was not helping, and that
he was becoming even more withdrawn. Moreover, he became incontinent,
so that he was no longer "acceptable" in a nursery school. In addition, there
were occasional episodes when his face would suddenly turn purple, and he
would have a far away look. We tried to get the doctor to see what was
happening, but we could not even get our telephone calls returned much of
the time. This was the first of several times that doctors blithely prescribed
drugs and then refused to recognize harmful effects that were immediately
evident to us. Another such incident occurred when Artie was about seven
years old. A neurologist prescribed heavy doses of an amphetamine. We
begged him to monitor the effects closely, but it was the same story. Perhaps
he felt we must give the drug enough time to act. We think that he was
looking for some kind of anomalous reaction of the drug, but it was quickly
and painfully evident that the drug was doing just what amphetamines
usually do. Artie lost his appetite, and would only eat a very few things. His
stereotypic behavior became even more persistent. Then, too, he was awake
until 1:00 a.m. night after night.

The Search for Services

By 1961. when he was five years old, it was apparent that there was no help
to be had for him in our area of New Jersey, not even an appropriate school
or day care program. Thus, when Art received an offer of a professorship
from Stanford University, and we learned that parents there had set up a
school for children like Artie, we decided to move. One of Art's colleagues
in the physics department had a daughter who was similarly withdrawn and
nonverbal, and his wife had been a leader in establishing the school.

The first year at Stanford was a good year for Artie, and the school
seemed to be something he enjoyed. But then the director of the school left
for a better position, and things did not go well for our son under her
replacement. Artie was not willing to participate in the group activities and
would wander off by himself more often. We sought help from neurologists,
which led us to the amphetamine incident recounted earlier, and from
psychiatrists. The psychiatrists, although they would probably not be classed
strictly as psychoanalysts, were influenced by that school of thought. Their
approach was just to try to get us, the parents, to search our souls to find
what terrible things we were doing wrong. Not only is this approach useless,
but it is also destructive, because it makes the parents less, rather than more,
able to cope with the difficult behavior of the autistic child. Also, that
approach immediately puts a gap between the parent and psychiatrist. If the

373

Our Son: The Endless Search for Help 7

psychiatrist insists on treating the parents as his patients, he cannot work
with them to help the child who is, after all, the person who needs help.

By the time Artie was eight years old, it was apparent that we could not
provide the teaching and companionship of other children that he needed.
The public schools had nothing at all for him in those days. But we did find
a residential setting, Clearwater Ranch Children's Home, which seemed as
if it could provide a good environment for him in a rural area. We placed
Artie in the home and visited him there weeklv. He came home for occa-

sional visits. After a year or so, he was moved to the Clearwater Ranch Town
House, in the small town of Cloverdale. There were six boys in the house,
and it was run by a wonderful lady, Mrs. Grace Turner. She had spotted
Artie at the ranch and asked for him because he had reminded her of a boy
who had started to talk while in her house. Artie learned many things there
and those were, on the whole, good years for him in which he gradually
became less withdrawn. He did not really talk satisfactorily then, but he
sometimes said phrases or sentences. Artie became able to do a number of
household chores and took pleasure in performing them.

However, at adolescence, several things took a. turn for the worse. Mrs.
Turner was not able to continue with the Town House. Artie grew big
enough so that he frightened some of the teenage girls who worked on the
staff. Even though at that time he never harmed staff or other residents, the
staff became particularly nervous when he began to have occasional tantrums.
Eventually, they decided that Artie was too big to manage, and we had to
find another place for him.

We found another ranch and he moved there. He was immersed in a
larger group and apparently did not get enough individual attention because
he became more isolated and withdrawn. When he began tearing up clothes
and sheets, this home decided that they could not manage him. However, he
still had never attacked nor hit anybody.

Hospitals and Teachers

In desparation, we put Artie into a state hospital. It was in a convenient
location, 17 miles from our home, and had spacious grounds. We were told
about their various programs and workshops, and it looked like a reasonable
choice. Besides, we had no alternatives, because there were then few group
homes for autistic adolescents and adults.

The hospital proved to be far worse than we feared initially. Somehow,
the classes never materialized, or would get cancelled after one or two
sessions because the person in charge was needed elsewhere, or for some
other reason, or for no reason. Worse than that, the hospital relied on
massive doses of antipsychotic drugs of the phenothiazine group (e.g.,

374
8 Integrating Modtrately and Severely Handicapped Learners

Mellaril or Thorazine) for behavior control. They insisted on drugging
Artie until he looked like a zombie. I don't think they had any idea of Artie's
abilities; under those drugs he looked and acted really stupid and half
asleep. The wards were quite chaotic with a lot of boys who would frequently
hit others. We brought him home for visits almost every weekend in order to
take him swimming, but under the drugs, it was difficult to teach him.

We continually argued with the doctors and with the hospital authorities
to reduce or eliminate the drugs. We were never told that the drugs were
good for Artie, but rather that the staff wanted them, or that he needed a
tranquilizer for such a violent environment. Not only did the drugs affect
his behavior, but physical side effects became evident. Thorazine made his
skin very sensitive to sunburn, and it was constantly irritated. Mellaril made
it nearly impossible for him to swallow. He still has a habit of holding saliva
in his mouth that originated when Mellaril prevented him from swallowing.

Eventually, we learned of the very great danger of tardive dyskinesia. an
irreversible condition that often follows prolonged treatment with these
drugs. Sometimes the authorities would yield a bit to our entreaties and
reduce the drugs; but if they had any trouble with his behavior, a higher
dose would again be administered. His behavior did become rougher, a
matter of sheer survival in that environment. At last, we found a newspaper
report of a court decision that drugs could not be given to patients without
their consent. When we showed that to the director of the hospital, her staff
studied it and told us that we could not speak for Artie on that because we
were not his guardians. We then went to the expense of getting a court order
of limited conservatorship which specifically set forth our right to control
his medical treatment. The hospital administration was furious, and tried
several times to get rid of us and Artie. But somehow, once the drugs were
gone, we found in Artie a warm and loving person, who clearly wanted
attention and was open to learning. What a contrast from the remote and
unreachable child we had known.

We, of course, wanted Artie out of the hospital. We tried several times
keeping him at home for extended periods. However, we could not find any
appropriate program for him in our community, and it was too much for us
to supervise him all day, every day. Since we couldn't manage to keep him
occupied at home, we tried seeing what a teacher might be able to do at the
hospital. A teacher who had some experience as a sign language instructor.
but was working on a college degree to acquire credentials, began visiting
Artie at the hospital to try teaching him sign language. It was pan of the
plan from the beginning that signing might also help him to relax enough
to produce some speech. She started with food words like candy, cookie, and
apple. The correct sign, or an approximation, was rewarded by a bit of that
delicacy. Somewhat to our surprise, he was happy to sit and work for an

375
Our Son: The Endless Search for Help 9

hour or so at a time on various signs. Although it did not seem easy for him,
he did learn a number of signs including those for some articles of clothing
and some familiar objects, and he made sounds with some of them. Most
striking was the word "bed" which he would say clearly while making that
sign. Sometimes surprising things came out, like "peanut butter." Apparently,
the effort of making the sign helped to overcome his inhibition against
speech. But neither then nor subsequently has he been in a situation where
he could really use those signs for communication, and so he rarely does.

What really seemed important was that he had acquired a taste for
working at a table with a teacher for extended periods. While he was still
working on the signs, we were able to hire an inspired teacher, Mrs. Joanne
Glass, who began to work on recognizing letters, words, and simple arithmetic.
Progress was exciting, but after a few months, she moved to a better job
which did not leave time for working with our son. We hired students who
kept up the human contact but did not have the skills to make much
progress.

Learning and the Surprise of Technology

Meanwhile, we continued to visit our son every week, and we kept up
these visits even later when he moved to a residential home 65 miles away.
In many ways, this house and the accompanying day program were great
improvements over the hospital; however, the emphasis was on controlling
behavior and. as far as we could tell, they did not take seriously the possibil
ity of academic learning. Many of these things we did on our visits were not
academic either, but we did use letter cards every week. He learned to
recognize letter shapes by inserting them into the cards from which they had
been stamped. Each time he inserted one, we would repeat the name of the
letter and usually the word which accompanied it on the card (e.g., "L for
lion"). However, we only began to realize what he had learned when we
bought a Texas Instruments Touch and Tell 1 ". This device produces a
synthesized voice that asks things like "Where is the red letter Q?" or "Can
you find the small letter X?" Correct answers are given by pressing the
appropriate letter on the device and are rewarded by a few notes of a tune
and by the voice saying cheerily, "You found the small letter X." After a
slightly timid start, it was soon evident that Artie knew all of the letters of
the alphabet by name, upper, and lower case. He also had no difficulty when
the synthesized voice asked him to "Show me the letter for king," or some
other word. Artie had learned the alphabet.

So he knew the alphabet, but how much did he really know about words?
There are various packages of Word Lotto available with cards which bear
pictures of familiar objects and their names, such as "umbrella" or "shoe."

376
10 Integrating Moderately and Severely Handicapped Learners

He could easily pick out any card asked for by name and match it with the
right picture on the large card. Aurelia then printed the words on the backs
of the small cards and asked him for the cards by name. The first week he
succeeded in identifying the six cards presented to him and the next week.
12 more. By then it was apparent that he could recognize any card she
presented and was not just memorizing them at that time.

Next, Aurelia tried reading a beginning level story book with him. It was
a simple version of the old story about the three bears. Then she told him. "I
taught myself to read by underlining words whenever I could find them.
Let's see if you can find the word 'bear' and underline it." He was able to do
that right away, and it was soon apparent that he could recognize any word.
not just a list of words that he had been taught. He really had developed the
idea of how to read.

But how could he communicate what he was thinking? We were given a
most exciting clue during our trip to Stockholm in December 1981. There
we met Dr. Karin Stensland Junker, who is a renowned authority on autism
and author of the book Child in the Glass Ball. This book is about her own
autistic daughter. Dr. Junker told us that a young man, 24 years old. had
been brought to her office a few months earlier. He appeared very with
drawn and typically autistic, and sat seeming not to notice what was going
on around him. Yet he had learned to communicate by using a calculator
like device that printed out words on a paper tape. For instance, she asked
him, "May I have some of your tapes?" He replied (in Swedish). "No."
"Why not?" she asked. "Because it's no good when the sun shines" he said.
The device uses a thermal printer, and the tapes fade when exposed to
sunlight. Mats, as his family called the young man, understood that the
tapes faded; now, at last, he could express it. How marvelous! Just imagine
how frustrated he must have felt when he could not express his thoughts at
all.

We found out some months later that this device is a Canon Communica
tor* 1 , which is sold in this country for about $600 by Telesensory Systems
near our home in Palo Alto. We bought one, but our son would only type
words if we guided his hand and mostly seemed to want to bang the keys
randomly. Meanwhile, we were trying some of the other things described
earlier. We got the address of the Swedish boy's parents and eventually
received a letter telling how they had taught their son to read and type. We
were excited because we found many similarities between what they had
done and what we were trying.

The Epson HX-20 portable microcomputer became available late in
1982, with a full-size keyboard, a liquid crystal display, and a small printer.
We wrote a program for this computer which would present either single
letters or words on the screen with a series of dashes underneath, like:

377
Our Son: The Endless Search for Help 1 1

Viola ROnnlund
Vikingsvttgen 26
S-175 61 Jarf alia
Sweden

17-02 1983

Mr. A. Schawlow
Stanford University
Stanford, California 94305
USA

Dearltr. Schawlow,

Thank you for your letter of October of last year and I apologize
for the delay in replying. It has taken a while to compile every
thing and then to get it translated to English. I hope it will be
of help to you.

Here are some notes on Mats and how he learned to read and write
with the aid of a typewriter and later to use his communicator.
Mats' s sister, who is a teacher, and I, his mother, started to
teach Mats a kind of unit reading. That was as early as 1967 . We
were only able to teach him during his summer vacations and every
second or third week when he came home to see us .

We tried to make him point at pictures representing words which
belonged to phrases he was to read later. We asked him about each
picture and he seemed to understand us and pointed at the right
pictures.

The next step was to give him words . First he combined two-
letter, and then three-letter words with the pictures. For the
most part , he managed to match the right words with the pictures .

Mats lived at home between 1970 and 1975 and we continued the
way we had started - combining words with pictures . Gradually,
he managed to put longer words, five-letter words, six-letter
words , to the right pictures . We proceeded with short phrases ,
e.g., "The child is playing," "The rabbit is eating," and
these he managed to place with the correct pictures .

After this, Mats started making words from letters. I showed
pictures of, for example, a girl, a boy, an animal, a house, a
car, or a rose. We had mixed the letters and he chose the right
ones to spell out the word suitable to the picture. We kept this
up for about a year. Then he started spelling out two-word phrases .
These phrases were gradually increased to five words .

Some time later, we started reading books. I read aloud and Mats
followed each line with his finger. After a couple of pages, we
stopped and I asked him to show me where a certain sentence

378
12 Integrating Modtratel\ and Severely Handicapped Learners

appeared in the text . At about this time , I encouraged Mats to
practice writing the letters of the alphabet by hand.

Later on we started practicing with an electric typewriter. Mats
tried to answer questions from a book for children in second and
third grade (8-9 year olds) . The questions were , for example , "A

lemon is not sweet but . " Mats had to type out the missing

word on the typewriter. Another simple example was to answer a
question such as , "this animal you get milk from.' In most cases ,
he managed to type the correct answer.

We continued the reading - now going one step further - both of
us reading quietly to ourselves . After having read three or four
pages , I asked who the passage was about and what sort of actions
were being carried out . He progressed very well and his spelling
was remarkably good considering he had not been practicing diffi
cult words. We continued with this type of reading and are doing
so at present . By now we have read a great number of books . Nowa
days he uses his communicator to answer our questions. The
advantage is that he can always carry the communicator he got
three years ago.

Mats has typed several letters to friends and relatives on his
electric typewriter. However, I have always to dictate these let
ters or nothing would be done - he finds it difficult to take the
initiative himself. He can also write by hand and he has written
some letters in this way, though I must hold my hand lightly on
his . Right now I am trying to make him write by hand without any
support . Every now and then it works .

When it comes to reading and writing, we are hoping that he will
start asking us questions. We feel that this would be a great step
in our mutual contact and communication. We so much want him to
take an interest in the world around him instead of turning inward
into himself, but we do not know how to help him in this matter.

These are some of the methods we have used with Mats and for
the most part , we have had very encouraging results . I do hope
our efforts can be of help to you and that you will keep in con
tact with UB and let us know if you have any success . We wish you
all the good fortune and patience when helping your son.

Kind regards
( signed) Viola and Magnus ROnnlund

379

Our Son: The Endless Search for Help 13

BOOK

The program was written to ensure that nothing was entered if he hit several
keys at the same time. He had to hit the right key, and no others. Artie could
bang at the keys all he wanted, but nothing would happen unless he hit the
right letter, first B and then O, O, and K. Each time a correct letter was
entered, the computer would emit a brief tone. After the word was finished,
the computer would play four notes of music and print the word on the little
printer. This worked and Artie enjoyed it. although he still wanted a
parent's hand on his to guide him. Sometimes, he would do nearly all of the
guiding by himself, but he would rarely do it alone. Later, we wrote another
program that displayed and printed larger characters, up to seven on a line
rather than the twenty of the computer's regular character set. This was an
improvement, but he still wanted a hand on his.

Right now, Artie's primary problem seems to be motivation. He has not
seemed to realize that he can communicate with words. We are working on that
now. Instead of emphasizing the typing, we are getting him to point at YES or
NO or to circle the desired word. He is beginning also to use a communication
board to pick out which of his activities, or which food, he wants by pointing to
a word on a board. We learned in Orlando, Florida, last year about one teenage
autistic boy whose behavior improved dramatically when he was given a com
munication board to describe his moods. When he came to school, he could
point out whether he felt sick, angry, or tired. A communication board is quick
and direct, but the range of choices is necessarily limited. However, it does
seem to be working for Artie and gives him a verbal way to tell us some things.
We hope that his success with it will soon carry over into answering questions
by typing a word. Then we will return to the Canon Communicator* which he
can carry with him and which might eventually be used to express any thought.

To teach him to type, we have used the Epson microcomputer, (although
it is far from ideal) because we had to use a portable computer. Since he is in
the state hospital, which is thoroughly chaotic we can not set up and us

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Full text of "Optics and laser spectroscopy, Bell Telephone Laboratories, 1951-1961, and Stanford University since 1961 : oral history transcript / 1998"

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